1 - Cok guzel? Ha, Ummm. I assume this is directed at me. Sony seems fine without Pokemon? It's too early to call failure or success on a hypothetical device with so many moving parts that may or may not comprise said hypothetical system? Certainly, like with every manufacturer, there's much more going on than Pokemon. So pinning everything on it's presence or absence is foolish.

2 - No. What are you basing that on anyways? Hope? The Xbox brand had it's high water mark last gen, and Sony was still able to sell more consoles in spite of the mistakes thay made, as well as releasing a year later. It's reasonable to assume no Xbox console will ever be that successful again, but who knows.

3 - What does this have to do with anything? How it it germane to the op? I'm not going to waste time going into what's wrong with this idea beyond criticizing the fact that it exists in this thread.

4 - Again, has nothing to do with the topic at hand.

0% chance of actually happening.

dare their, were juts here too help!

Also when you use a small I you are only making yourself look small!

As for the OP, they have the Vita right now which plays a bunch of games which are also on the PS4 such as World of Final Fantasy and Digimon Story: Cyber Sleuth.

Sony should stick to consoles and Nintendo should stick to the hybrid/handheld market. It is better to focus on making one thing great instead of splitting versions and making things just ok.

Keep in mind, if scaling down was as easy as you say, the Switch would have a lot of 3rd party support already. If Sony were to make a portable PS5 (or PS4) for that matter, it would affect the release and overall performance of their high end consoles. Devs always focus on making things work on the least commom denominator after all.

Plus they would likely be destroyed by the Switch due to existing install base in terms of handhelds. It would not be that much more powerful and would have more games. It would be the PSP or even worse, the VITA all over again.

Nice try, but this is a horrible idea for Sony. The reason it works for Nintendo is because their recent consoles have not been about power and they have a massive hold on the portable gaming market. Sony on the other hand...not the same story.

"Sometime in the 2020's"... as in all the way to 2029? I really don't feel comfortable predicting anything about the console market much more than a couple years in advance lol, the looming streaming question is just too large to ignore.

It's an interesting thought, but I don't think it's gonna happen. First of all, I am not sure they could have this level of hardware at a reasonable price/battery life anytime soon (unless we are talking 2023+), second, Sony does not benefit from uniting development like Nintendo did - they don't have their own dedicated portable studios anymore, do they? Third, Sony is a very rigid and traditionalist console maker, generally - the only way I see it happening is if someone else pulls off a similar concept well (though that might be well on its way, the Switch is doing good!).

PS4's chip even at 7nm would consume way too much electricity to be feasible in a reasonably sized portable.

You're likely looking at 30 watts still just for the chip.

Playstation 5 portable is a laughable proposition unless Sony is cutting off their knees and making a system that's basically a PS4 Pro redressed, in which case, Microsoft will be able to exploit such a weak new console and take over the home console market. Simply cutting the resolution by 4x only saves you so much.

Sony could make a custom chip portable with PS4 tier visuals by around 2020-2021, but it would require PS4 games to be ported from scratch to a new architecture  ... and Nintendo could very easily counter that with a Tegra X3 based Switch which would be compatible with (by then) hundreds of Switch games and Sony is back in a bad position.

Sony has routed Nintendo out of the dedicated home console space, they can enjoy the fruits of that, but portables are likely always going to be difficult for them, moreso now because Nintendo's majority/entire focus is one basically the Switch ... Sony will never be willing to make that level of commitment to a portable platform. Is Sony willing to put Uncharted 6 as a Sony PSP3 (or whatever) exclusive? Not a spin-off but the actual next game? I doubt it. Nintendo is willing to put major IP installments on their portables, Sony has never been willing to go that far. 

1. R2/R3/L2/L3 inputs
2. SD Card support
3. An unlocked 4G model
4. A dock (Would use DS4 for the controller)
5. Would need to be within 10% of the Switch's ability
6. Cross Buy would need to be a must on all titles also available on PS4/5
7. Full BC from all Vita-supported titles.
8. Full support from all PS2 Classics available on PS4.
9. Should aim to have most 3rd Party Switch titles port over.
10. Should aim to have compatible PS4/5 titles port down.

Or you could just buy a Switch which would have the same games + Nintendo's full 1st party backing. 

No doubt about it. The goal is to get as many people as possible connected to your ecosystem, and keep them connected 24/7. For Sony to continue to expand, they have to give consumers more ways to connect to their ecosystem.

Scalability is absolutely the name of the game going forward. One purchase working on all Sony devices going forward it going to become mandatory as Microsoft, Google, Apple, and the rest are making this the standard. As you said, the Pro is just the first step. In the future we will have PlayStation devices from $99.99 or less, to $999.99 or more. Sony will give people options from streaming boxes to top of the line PC specs, and a basic portable to a full fledged phone.

PlayStation mobile products should arrive in the next two to three years. Whether they are running on 7nm PS4 tech, or more advanced Ryzen Mobile and Navi tech is the question at this point. Sony will continue to expand the PlayStation ecosystem. PlayStation Vue and PlayStation VR are not the end of the road as far as growth at PlayStation is concerned.