Having played in aspect ratios other than 16:9 I have come to appreciate performance increases without sacrificing resolution for what remains on screen. For some games, not having a view extending to the sides doesn’t impact gameplay much, such as Portal 2.
Has anyone tried a 1:1 aspect ratio with the steam deck, either with the main display or an external one? I’m curious as I have a 1440p monitor, and if my calculation is correct 1440p in 1:1 aspect ratio (16:16) has the same number of pixels as 1080p in 16:9. It makes sense to concentrate pixels in the centre where you will be looking rather than spreading it out to side that isn’t necessary to see in some games. I feel like I can get used to different aspect ratios if I get engrossed in a game.
Not 1:1, but I did remember someone saying Control runs better in 4:3.