I think the issue of gaming on linux hasn't been performance for a while now (native and wine/proton performance can often beat windows) but compatibility - some games still can't run on linux due to DRM, anti-cheat, etc. Things are gradually improving but I think that's the main barrier for the time being
if the main barrier for entry seems to be compatibility (which is totally fair as DRM and anti-cheat can be a real pain in the ass) hopefully wine/proton (aka Steam) can come in clutch to help solve most if not all of these related issues (or anyone else that has the know to and desire to create another copyleft compatibility layer)
It's totaly messed up in general and has been for a long time. They try to hack it for the new CPU model and stab you in the back for older CPUs, I'd say it is FUBAR.
From my experince AMD drivers are pretty close, I'd even say slightly better on GNU/Linux, definitely more stable and consistent. For Nvidia, yeah they are bad at supporting GNU/Linux. Improved a lot through the years but still not there. For Intel, well not exactly an option for gaming, at least not the integrated GPUs I have used so far, but still better than in Windows in a similar way as in AMD case.
P.S.
Another great thing with libre/opensource GNU/Linux drivers: When you report a bug with Mesa3D drivers the bug is quite quickly fixed, especially when you can provide them with backtrace and/or Vulkan/OpenGL API trace. Doing a bisect of source code commits amd identifying the commit that introduced a regression also help a great deal. Good luck doing the same with closed/Windows drivers: you can wait for years and no fix.