How much have you looked into game compatibility on Steam Deck?
Roughly 75% of Steam's top 1000 games will work on Deck without too much trouble. For me, it's more like 90% of my Steam library. In my experience, the vast majority of games just work. And Proton is constantly being worked on, so compatibility is ever improving.
The largest problems with game compatibility on Steam Deck now are a) the hardware - quite a few recent releases are simply too demanding to run well, b) some DRM being incompatible with Linux, and c) some online games not working due to incompatibile anti-cheat software implementations.