99,9% of all games I "own", I can play on Linux just fine. Except fucknuggets like destiny2, which you technically could play if only bungie allowed it. Might look slightly different if you only play multiplayer, I dunno. Those with aggressive root - kits anti-cheat maybe.
Actually I even game better now. Before I made a tool just to be able to pause a game at any time, which worked like 50% of the time, sometimes fucking all up. On Linux it's a small script with 100% success. To me, a major improvement.
I still have a windows drive for "emergencies" when a game won't run. Haven't booted it since I switched in January. And I game like 4-8hrs a day (with breaks) with different games all day.
Thanks to steam's efforts, Linux gaming is absolutely viable. All is fine, performance, HDR, sound, input...nothing is worse now.