I've had the deck same length of time & I disagree with you
Games like F1 2025 are labelled as unsupported (won't run) even in single player mode because of anti-cheats built in. There's lots of others which would play well on the deck but are just the same. Pretty much every new game these days has some form of anti-tamper/anti-cheat built in and they're all labelled as "unsupported on steam deck" for that reason. Plenty of older games/games without drm/anti-cheat but newer ones are becoming an issue.
Bazzite PCs are a different ballpark as you can easily dual-boot them if necessary & games which do run usually run better than on Windows.