I have rewatched the presentation and gameplay footage on youtube. this is what I think:
First party games: They will look and run excellent because they will be designed for the limitations of the switch 2 limitation.
3rd party games: I think the performance will be highly variable depending on how poorly/optimised the fame it. Indiana Jones and the Great Circle and Kingdom Come: Deliverance 2 are the only recently released games that have launched in a state that's optimised. They run well on even a 3060. Meanwhile, some recently launched games, run terribly on a PC with 5070 and 7800x3d. Few recent titles can barely be played without DLSS.
I wish that the Switch 2 would receive PS4/Xbox One titles. They run much better than their remastered version. Good examples are remastered versions of the Last of Us and Horizon Zero Dawn Remastered. The visual improvements don't neccessarily justify the 30-50% frame rate. For those with older GPUs it's better to play the original. I think the same could be true for the Switch 2.
Sure, it has DLSS and FG but those can'tbe relied upon if the base frame rate is super low or if the device is running the game at potato graphics settings.