If the Steam Deck can play virtually every single XBox Series X title and would be able to play every PS5 game if Sony would make PC versions available of every game ... then I think the whole "Switch 2 can't possibly run those games" is already been debunked.
I can't even find a major XBox Series X game that doesn't run on the $399.99 Steam Deck due to performance, and frankly all the games look pretty damn good on that little screen. It's not like some hugely compromised version that's barely playable.
Anyone saying "60 fps or it's a totally different game!" is selling a load of bullshit. By that logic you can say the PS5/XSX don't have next gen versions of any game either since they can't run any of those games at like 120 fps like a higher end PC can and thus the PC version is the only legitimate version. What kind of fucking dumb logic is that.