Linux gamer since 2020 here. While obviously not perfect, things are getting better at amazing speed. Between Linux getting better and Windows getting worse at compatibility, your 3-year timeline looks very doable.

Though multiplayer games will remain a pain point for the foreseeable future, due to anti-cheat shenanigans.

(Also, sometimes the compat is there, but figuring out how to enable it is a pain. d3dx* being a good example; for me, it was selectable in winecfg menu, but wasn't installed until I figured out winetricks. Steam and Proton issues are much less obtuse.)