Gaming on Wayland, or more specifically sway WM, broke for me when updating to nvidia drivers version 580.
Reverting to 570 fixed the problem.
Card: Nvidia RTX 3060 Ti
What exactly happened: some games wouldn’t launch at all (overwatch 2) while others had severe performance issues (Resident evil 5).
Those were the only two games I tried. Both ran through steam and Proton GE version 10.
Though I didn’t test extensively, both games seemed to work fine on Xorg with nvidia drivers 580. So this confirms it’s only problematic for Wayland.
Gamescope is developed by Valve and used in Steam Deck. But you can install it on any system. You can think of it as a commandline application, to run games with. It can fix issues you or give some options and should make games run better if they are problematic otherwise.