Short-term option, doesn't account for long-term ramifications of consolidation.
Sony can do both, FWIW. They probably already have marketing rights to GTA 6. But yeah, a GTA 6 bundle only addresses the immediate market situation, not anything 5-10 years out.
5 to 10 years out if people haven't embraced Gamepass then Xbox is fucked. If Gamepass/streaming is the future (like a decade out) than MS probably wins, if it isn't then MS gaming dies.
Sony Movies could make Nintendo Movies
Crunchyroll could make Nintendo Anime
Sony Music would benefit Nintendo a lot
Consoles would have access to the entire retro Playstation games as well as Nintendo (Sony has made games for the Snes)
Sony Charecters in Smash Bros
Playstation studios will share tech with Nintendo ones
A lot of proprietary hardware is owned by Sony and licenced out to other companies
The first two seem like they would actually hurt the owners of Nintendo IP, by limiting who could make pitches on it. Especially in movies, since last I checked Sony doesn't have a big budget western cartoon studio.
And I don't see how Sony Music benefits Nintendo, like, at all.
The next two are, honestly, really small potatoes, especially the Smash one.
Useful, but only so much so, isn't all the tech on all of these boxes contracted out to chip makers now anyway?
This, on the other hand, is an actual benefit, and one that goes both ways.
But when it comes down to it, you are asking to either support two separate consoles (a Switch 2 and the PS5) or to abandon the switching model in favor of the PS5's standard home console set-up. I cannot possibly see that growing market share versus the two being separate, or removing duplicate costs enough to make it more profitable than having two systems, ergo shareholders are better off with the businesses being apart than they are with them being together. All speculation anyway, since regulators would never allow such a merger anyways, under current business conditions. That might change in a decade or two (see: Sega in 1992 versus Sega in 2002) but its clearly off the table for now.