I’ve switched my KDE setup to Wayland a few months ago and have seen a performance increase on some of my games. For example, Cyberpunk feels much smoother than under X11.
But I’m facing the same issue you’re describing in the native Linux build of War Thunder. It runs at a stable 144FPS on X11 but regularly dips down to 20FPS on Wayland. I initially thought it might be the NVidia drivers, but seeing that you’ve got an AMD card, I’m not so sure anymore. For now the fix is to just switch to a X11 session if I want to play this specific game. I don’t think KDE will drop it anytime soon, there are still a lot of random quirks in Wayland at this point.
There are also white and green ones to spice things up a little.