Well, gaming on Wayland works to the degree that GNOME works. I spent a while on GNOME running it exclusively as a Wayland compositor and did a fair amount of gaming on it and for most things it was just fine. Some things seemed to crash inexplicably but most games just worked.

The bigger issue is that GNOME is a god-awful Wayland compositor and, in my opinion, cannot be trusted to meet stability and frametime requirements. All of GNOME runs as a big behemoth of a pipeline and if something somewhere takes too long or breaks, the entire structure either freezes or collapses, which is particularly bad on Wayland since it means frames won't be delivered or your entire session is lost.

So I am more hopeful for the smaller compositors, which sadly have their own issues. Sway has been going through a big move and has only been shipping RCs (which I can't build for some reason) and last I checked it suffered from the mouse capture issue that is common among other smaller compositors like Weston and makes playing first-person games quite hopeless.

KDE I have not looked at much, but it was half-working for gaming when I tried it. It seemed to have the mouse issue somewhat under control though.

KDE/KWin is getting better. Here is TW3 running in KWin Wayland session (using XWayland):



So far dxvk though needs a workaround setting in dxvk.conf:
dxgi.numBackBuffers = 3
to avoid hard capping of framerate which ignores vsync setting.

No mouse issues so far. But Wayland session still has a few other non gaming related bugs which make it annoying to use.