Do you have anything more tangible than "lol"? Looking at the most played steam charts, there is about 10% that has anticheat that does not work on linux.
In the top 10 I see only 3: pubg, apex, and rust (no idea about delta force) but unplayable on the steam deck and whether the anticheat filters out linux are not the same.
???
Oh right. ‘Except for games with anti cheats’ - so like, at least half the market lol, and more than 90% of games by game time.