If Switch fail, all these assumes that Sony copy Nintendo to make a hybrid won't happen, right? And Nintendo own Japan like Sony own Europe. In 2020, New Switch can come out with new Pokemon, counter it by what?

If Switch fails then Pokemon doesn't matter to PS.

Pokemon single saved GBA in the past, it doesn't matter to PS because Nintendo own it. Pokemon can change fate of a portable and sell 20 million or even more each installment. If ps4/5 portable sell underwhelming, what Sony franchise can do that?

Worked in the past doesn't guarantee it'll work now. It makes the odds higher, but you can't always rely on that one juggernaut. Look at XB and you'll see what eventually happens. Again, PS may not have a game franchise quite like Pokemon, but they have such a vast variety of many quality games, that the odds of the system failing is very unlikely due to the games. If the PS portable were to fail, it would more than likely be due to a hardware, online, price or marketing problem.

Except it always true since GB/GBC, GBA, DS then 3DS. PSP sell good because two thing: Monster Hunter in Japan and multi media in the West. Now one aspect is meaningless, the only left is Monster Hunter. Now, let me address my concerns for a possible Vita successor in the respect that it may struggle to find a place in the market to combat Nintendo and Switch.

- Established Portable IP

Okay, it's no secret that Pokemon is the main reason millions of people buy a Nintendo handheld console. At one point in time, I would have said that Sony should money hat Namco Bandai for exclusive game rights to the Digimon series, however since that series is nothing in the public eye to Pokemon anymore, it would simply be redundant. Nintendo IP just seems to be perfect for home gaming or portable. Fancy relaxing at home, try some Mario Kart. Want to kill some time on the journey to work? Smash a quick level or two on Yoshi's Woolly World. Do you want a console like experience on a portable where you can just vegetate and get lost? Zelda is your thing. Is your handheld console your primary console and you want a game that will last you for a long period of time? Boom, Pokemon. 

Sony just don't have the IP in their library. Little Big Planet is as far as it comes to intellectual property ideal for portable gaming and sadly the scope of it makes it far more complex than Mario if you truly want to get the most out of the game. Honestly it's ideal for portable gaming, if you truly get into the Play, Create and Share aspects of the game. Problem is, many people don't. Media Molecule were the only big Sony Studio apart from Studio Japan to support the Vita and that's where it hurt a lot. I'll elaborate on that in a moment (Sony Bend weren't so much a thing then.) But quite honestly Sony lost Monster Hunter because of their lack of dedication to handheld gaming, they lost Yu-Gi-Oh! because of diminishing sales. All the momentum they built with PSP they killed with Vita and it's a shame because they are two very different devices.

- Nintendo Studios can thrive off handheld only sales

Here is a question Sony need to ask themselves. Can we fund and support a studio that could operate solely on sales from their portable platform? 

I don't think they can. They need a huge install base and an IP that sell's portable systems. 

They need to sell at least 500,000 to 1 million+ copies per game to survive, based on a two year development cycle and a small team. 

Nintendo can happily keep studios independent and on 2DS/3DS only because they make a healthy profit. Sony are admittedly greedy and they always want more, they always push for more and gamer's benefit from their drive to push beyond the boundaries they keep setting with the first party titles. The emphasis on portable gaming needs to be short bursts of handheld fun and honestly, I don't think a Sony studio has conquered that feat yet.

Lets's just say for arguments sake, Sony open three studios, or even just create three additional teams within existing studios. Three games over a two year development cycle. They pay all the costs for setting up, software, wages, trademarking etc. (Assuming they don't use current IP). They make this new console and it bombs. That's a ridiculous amount of money to lose on a whim. The Vita killed Zipper, even though Unit 13 was a solid game and Motorstorm RC didn't exactly sell like hot cakes, even if it did get Evolution one more crack at a game. Sony Japan didn't think much of the Vita by not releasing Gravity Rush 2 on the Vita, when Gravity Rush 1 was an amazing example of why you should own a Vita. 

- Vita ruined a lot of good will Sony built with PSP

I can't stress that I love my Vita. I am still fucking annoyed that Soul Sacrifice has not been ported to the PS4 yet. Persona 4 Golden is one of my G'sOAT and Uncharted Golden Abyss, courtesy of what people say, is a great Uncharted game. So please don't think I'm needlessly hating. I loved my PSP dearly and I still do. I love my Vita just as much. But consider the average consumer who isn't a PlayStation enthusiast and the common complaints from consumers.

[1.] Point of entry is too high. £229.99 was a hell of a lot for a portable console when 3DS was £159.99 after a price cut and trading in a DSi reduced the price further to £89.99.
[2.] The system used specific memory cards. This was a further cost and quite honestly they weren't cheap. My 32GB card back in the day cost £79.99 making the purchase close to the price of a PS4 and more than a PS3 at the time. No internal memory either.
[3.] We stayed at 3G and not 4G and the data plans Sony arranged with mobile networks were quite honestly, shit. I was getting unlimited 3G a month from Three, promised 4G as soon as they launched at no extra cost for £22.00 a month, with an Xperia X10. The cheapest deal in the UK was Vodafone for 2GB a month at £19.99. No fucking thank you.
[4.] The charger was specific and not generic. Something addressed in the future Slim Vita which solved a lot of problems. These chargers damaged easily and they weren't affordable either.
[5.] No killer app on release. I remember getting Little Deviants, Uncharted: Golden Abyss and ModNation Racers. The only good game was Uncharted. I waited weeks for Gravity Rush, Soul Sacrifice and Unit 13. Great games were coming, but that was the problem, they were still some ways off.
[6.] It just had no games for months. After the initial wave of 22? The release schedule just died. Nintendo had loads on the horizon, no pun intended, but Sony just didn't have anything. They just kind of expected it to sell gangbusters and it didn't.
[7.] Battery life was incredibly poor. This was a massive complaint I used to hear all the time. I only get four hours out of it. It created a bad stigma with people I knew well within the local gaming community and many were put off. Thought it has to be said, this was also an issue for the 3DS.

- Sony are always conscious of piracy

Which is a fair point because they had a lot of security with the Vita that just quite honestly was a little overkill. The problem is R4 cards were hurting the 3DS and probably still are. I remember an article from a Japanese developer who said he remembered being angry going to drop his son of at school and seeing that everyone was using an R4 card in their 3DS and getting their games for free. Literally denying his company thousands of yen which have been pissed out of the window. Kindness and nice thoughts don't pay these peoples wages and since the 'Random number is 4' escapade, Sony really want to tighten up and may make a douche bag move like using bespoke memory card which cost a bomb to avoid piracy but throwing up a barrier to entry.

- Sony always want to offer the best... but it comes with a price

It has to be said, the glowing OLED screen, the premium dual analog sticks and d-pad. The excellent build quality and feel of the Vita. It's a beautiful device but it came with a cost. The OLED screen quite frankly wasn't necessary and jacked up the cost a lot. I feel if Sony do try to make a Switch competitor, they'll lose focus and go right in for a 1080p or above screen that's going to cost a lot to make. They won't emphasise battery life. It'll be all singing, all dancing and it will accomplish nothing. It'll come with a high price point and it won't sell. That's just the nature of the beast if they repeat their decisions with the Vita. 

Watching the NGP announcement, I was amazed by what could be done with the Vita and couldn't wait to sink my teeth into it. Yakuza 4 on the Vita, Ninja Gaiden on the Vita, all looking like PS3 games. It was great. But ultimately failed. The second Nintendo dropped the 3DS price point just before the Vita launched, many of my friends had made their decision. They went with 3DS and that was just one of those things. Price does dictate the market for millions of consumers. 

- It'll get panned for being a 'Switch' clone

Assuming they don't fuck up by releasing an over price, premium handheld gaming device with a meagre selection of games, stupidly priced accessories and no built in memory, the press will just accuse Sony of once again copying Nintendo. Even though Nintendo are quite honestly, credited with a lot of things they didn't really innovate, it'll just be another bias comparison to Nintendo's offering. It won't receive a positive impact and it won't gain much traction. I can see it a mile away. Just like Sony got thrown under the bus for releasing their long in development Move tech to combat the Wii success, because quite honestly Nintendo beat them to market, they'll just be a point of comparison. You'll get another 'Sony copy Nintendo' meme and it'll just be bad press all around.

Vita clearly didn't go over well, much like Wii U didn't, which would be why Nin would 'merge' and create Switch, and why PS could 'merge' and create a PS Portable (PS Swap, PS4P, whatever). Comparing a new PS hybrid to Vita doesn't make much sense since it would need to be set up very differently to even stand a chance, which is partially why the initial question was asked in the thread. It's also the reason why we have been throwing around so many different idea's, because if it was as simple as just make a stronger Vita, PS would have done it, and this thread wouldn't exist. If a hybrid can work for Nin by offering it's console games on a handheld, and also getting handheld games made for it, it only stands to reason, like you said, that based on history, a PS hybrid could very well have similar success. Whether it would or not depends on many things, but to suggest PS would just copy Vita and hope for the best is a bit naive, considering when a similar 'poor sales' situation happened with the PS3, they dropped that ecosystem and went in a completely different direction this gen. That direction btw, was extremely logical, and safe, and has worked wonders for them. Who's to say they can't do the same for their handheld business?

When sony studios make game that use all power of home console we have Horizon Zero Dawn on ps4. But with ps4/5 portable, they need to downgrade a lot graphic setting, FPS. resolution and must guarantee the system last 4 -5 hours like you people said. You think they can do that now with a $250 handheld and the impossible battery last 5 or hours? 

The basic answers for the question in the thread title lie in the Switch and what Nintendo does right now. If you look close enough you'll see that right now Sony can't and shouldn't pull a 'PlaySwitch'.

First of all, the kind of games Sony has right now. Those are totally for gaming at a console. Unlike that Nintendo has way more games that suit mobile devices or both. If you want Sony to make the games they do best right now, that's pretty much a living room experience.

Power. If it's for the kind of games, what people simply expect from Sony or stuff like VR. Sony can't go that easily for less power but mobile like Nintendo did. Instead most will want someting really powerful. I mean we already have that PS4 Pro. That would leave Sony to developing games for two systems again.

Classic handhelds are dead. Let's be honest. Switch is about the size that Game Gear and Lynx had back in the Nineties. The high end devices, that lost over a way more mobile handheld. Why? Something has shifted massively with handheld gaming. Yeah, smartphones are for playing small games everywhere. A handheld basically has to be a premium experience with premium games. Being able to do the Switch is one key here.

Nintendo only managed that by combining the handheld and home console market they've had so far. We can be pretty sure there will be no 3DS successor with Switch being a massive hit. And it doesn't seem like there are still many Nintendo games coming for 3DS.

Sony's only real way to really counter that would be to do one device with less power than the Pro already has and hope that gamers might follow them. While people buy PlayStation for the higher power living room experience. And that after Vita was a failure.

No, Sony shouldn't do a PlaySwitch for quite some time, if at all.

- It will be more expensive for those AAA games to also be played on the go

- Discs to Cartridges (It could impact those 50gb+ games) 

- How about Hard drives. You have games now that takes sooo much space for updates and dlc. People now have to rely on SD cards? 

Unless they have the compressing abilities from Nintendo, I cannot see how these games can be reduced in size. Doesn't 1TB storage cost a pretty good amount when creating a console? Add that to a battery that will have to last at least 3-6 hours for these games that push hardware tech among other things can be potentially costly. It could work, but I don't see it cost less than $300 with the tech aged as it is now. If Nintendo are not selling at a loss with the Switch, I don't know how Sony can eventually make this supposed PS4-Switch not bleed too much money.