Somewhat relevant might be these companies´ own opinions.
Nintendo has repeatedly reiterated it´s ¨blue ocean¨ strategy which is premised on not competing but instead operating in non-competitive niche.
I believe Nintendo has been successful as of late which would be strange to happen meanwhile the company is ignoring the supposed competitive reality.
To the extent there is competition, I think it is small element, and that could be said re: any consumer entertainment/hobby (ice-skating, alcohol, etc).
I think if Sony launches a hand-held that might open up more direct competition. But it could very well happen that they exist in separate niches.
Being classified as ¨video game console¨ doesn´t entail direct competition, no more than ¨home electronics¨ entails Nintendo is in competition with blenders.

Some people here talk like if players' taste on videogame were stable and unchangeble. I know that there are people that probably wouldn't by Nintendo's consoles or Sony's consoles because it isn't their "thing" but these companies know that, at the end of the day, everyone buying consoles wants to PLAY VIDEO GAME. Mr. Random would "never" buy a Nintendo console because he prefers mature, realistic, movie-like games but maybe Nintendo does something that calls his attention to the Switch. Maybe this guy takes an interest on one of Nintendo's game for whatever reason or gets interested in the the hybrid form of the Switch, and BANG, here we have a person giving $300 to Nintendo to buy its game instead of giving the money to Sony. To sum things up, think of a Venn Diagram. The interconected part of the circles are the people who usually is really torn between buying Nintendo's or Sony's stuff and the the outer part of the two circles are people who usually wouldn't consider buying the console of the company they don't care. But pay attention to the USUALLY. Companies deep down will always want to get as many people to its environment, even the ones that supposedly will never like their stuff

Is that still a thing? I'm around a lot of young people, and it seems like Nintendo is cool again. I haven't seen the kiddy thing in a long, long time.

They are both fighting for your time and money. The segment of the market they appeal obviously has overlap between people who owns both platforms Therefore, yes they are competing.

Heck, people should really stop using the Switch is "seen as a Handheld argument" cuz Nintendo has already put proof that most of the userbase uses the docked mode predominantly, therefore they do in fact target in part the same market demographic.

According to Nintendo themselfes most people use handheld and docked the same time, but more people play handheld only than docked. You can check that in ir.nintendo.com. If more people played docked only, why is there the Switch Lite, a HANDHELD ONLY model, but no Switch TV, a docked only model? I think that says it all... About this competition thing: I do not fucking know why this is even a debate? All over the internet its a widly accepted fact that both are in competition, only here on vgchartz this seems  to be a problem for some people. At the game awards Nintendo games are in the same cathegory as Playstation/ Xbox games, on gaming exhibitions all big 3 are present, nobody argues why Nintendo is a bon competitior. If anything MS slowly starts to get out of the race: Hardware sales are NOT IMPORTANT (!!!), exclusivity is a THING OF THE PAST (!!!), physical games will be gone next gen (ok for PS6 as well most likley but MS makes the first Step). If anythink MS is not competing, they even release games on rivallimg plattforms. DOES NINTENDO RELEASE GAMES ON RIVALLING PLATTFORMS? No? So they seem to care about exclusivity. They don't want you to play their games on RIVALLING PLATTFORMS, so they are in COMPETITION!! Sony releases their games on PC? Why are they doing that if the PS5 was tgeir main focus?! Some years ago i've been told by fanboys that this would "never ever happen"!! If i was in charge at Sony not one single first party would get wasted on a brokem 3rd class plattform like the PC!! I would keep everything exclusive at ALL COSTS, even if it would cost me millions!! PC gamers would cry they want a PC version but soon realize that our games would only be on Playstation, so many would at least buy a PS as a second choice system. I would offer them experiences only availible on Playstation. I would revive the NeGCon a twistable controller and add force feedback to it! The same goes for the JoGCon and the G Con Light gun. I would keep it exclusive om my console at all costs no matter ehat investors say. That would pump the value of my system. Right now Playstation is starting to loose its soul. Where arr the games i can ONLY PLAY ON PLAYSTATION and not on PC(/Xbox/NS)?! If Sony (Bamco) decided to make a new G-con Light gun i would even help founding if necessary!!

*Looks at the homepage of vgchartz* Yep, they still compete with each other.

Your arguments againt are not very convincing. The music analogy doesn't work. If you were talking about 2 specific games that have different audiences, then I could get behind it. It doesn't work well because both systems offer a range of overlapping games and genres.

Overlapping users doesn't mean there isn't competition. If a game comes out on the Switch I want to play that means I'm spending time and/or money on it, and not the ps5.

The form factor of these systems is irrelevant.

Your arguments in favor:

1) Yeah, that.

2) Yes, that is important and I get back to that in a minute.

3) WTF is a core gamer? It has nothing to do with skill, because many games that are declared core I can play and win and many declared non-core I cannot. Like Mario or other Jump&Runs, too hard a skill need for this. I really enjoyed the style of Rayman Legend, but I became stuck halfway through as I wasn't able to beat the levels there the critters are following you and creating an time limit. Rhythm games in general are considered casual and I can have fun there - but they beat my unrhythmic ass. Skyrim is much, much easier than these.

4) That is similar to the money argument 2 and is true. For competition in the market money is the more important metric though. Although one can follow the other.

Your arguments against:

1) Mercedes and BMW have each their fans, and you could argue a BMW afficionado would never buy a Mercedes, therefore they are in different markets and do not compete. The truth is though: fans can be converted, tastes can change and they still offer a product in the same category and compete for your money.

2) And this one does not make sense as an argument against them competing. Assume a guy who has bought a Switch and a PS5. Do Sony and Nintendo now stop to compete for his money? Nope, they still want to sell games and in-game purchases. Even if that guy owns Fortnite for both platforms, each want to make him play on their platform, as I understand that Nintendo and Sony get their cut if he buys V-Bucks through their shop. Or say two guys with both systems consider which game to buy. One gets Horizon the other Zelda. Who makes more money? And if they play and enjoy it each, on what platform they are more likely to buy their next game? There are more than one Horizon and Zelda game on each platform, just for starters. So yeah, people who own both systems are a hard compete market.

3) OK, fine. Our guy plays TV games at the PS5 and pulls out the Switch while on the train. And then he gets to a game playing portable that pulls him... getting home he don't want to stop and keeps playing on the TV. Oh, now they compete.

100% agree!! 

@Mnementh

Thats what i mean! We are not in charge to consider wich is competitionnand what isn't. If anything, Smartphones are not comoeting with consoles, mobile or stationary because tey belong in a different cathegory: Smartphones! A rowmower does not compete with a motorbike just because both have wheels and an engine.

Sony always saw Nintendo as competition, conferences always had slides were they were outselling Nintendo consoles with a big margin but they stopped doing it during the PS3 era when it was clear Nintendo Wii was outperforming the PS3 in sales.  Example

Thank you! That says it all! Sony does compete with MS and Nintendo. In the past Nintendo and Sega even made adds which downplayed each other and Nintendo was playing over the top with their Rumble Pak directly adressing Sony in their adds. Also never forget: " Hey Plumber Boy! Your worse nightmare arrived!!" Of course they did not want to admid they were defeated when the Wii was outsellig the PS3. Strangley MS never acted like Nintendo was no competition...

/threat