ElQuintron FWIW I've been using Linux fill time for over 6 months now, and the Steam Deck since launch and I've yet to encounter a single player game I can't play.
I was starting to dabble in Linux, but then I switched away from Windows after the first Windows 10 'feature update' caused my PC to BSOD. I was able to fix it by deleting a driver (using Linux to access my Windows files), but it turned me off to Windows, especially as they were on the path to becoming more intrusive.
That was about a year or so before Proton came out. When Proton came out, I didn't have a reason to dual-boot anymore.
I'm in the same boat. I can't think of a game that I've wanted to play that didn't work in Proton/WINE (or wasn't already Linux native). I've come to the point where I just expect games to work now.
But, I'm not big on multiplayer games, and I've heard those have issues, so it might not be for everybody.
Realistically, I don't think people are going to change to Linux, specifically for gaming. It's just that I don't think gaming is a massive barrier to changing anymore.
I don't have a Steam Deck. I've been kind of interested, but I'm not sure if I'd do enough handheld gaming. I can barely find the time to play on the desktop.