Riot Games doesn't commit to Linux support anymore. There used to be ways to play League of Legends on Linux, but that's broken now. The other big broken titles (currently) are Rainbow Six Siege, Destiny 2 and PUBG: https://www.protondb.com/explore?sort=playerCount

That being said, pretty much everything else works fine. Running GTA V Online, Overwatch 2, and the majority of popular Steam games should be as easy as clicking "Play". Do your research before committing to the switch, but I think you'll be pleasantly surprised by the game compatibility these days.

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