I switched to Linux Mint a couple months ago and use Steam a lot. I’ve tried at least 10 games and all worked perfectly.
But I don’t do competitive multiplayer. Those are more likely to have issues with anti-cheats. Although I did try Hell Let Loose and Helldivers very successfully and those are both major online titles.
Check protondb.com if you’re worried about a specific game’s compatibility. I’ve had silver rated games work perfectly though.
Edit: Apps - Photo editing and 3D CAD are the main areas I’ve struggled with on Linux. There’s no good Adobe equivalent, and no good Fusion 360 equivalent. Free CAD exists, but that can gently fuck off.