I've been running Linux full time for quite a few years now, and i have a 512gb Steam Deck. In my experience, 80% of my library just works without tweaking due to proton. Maybe 15% requires minor tweaking, easily found instructions for online, the last 5% either requires major tweaking or just flat out doesn't run. Most of those don't run very well on windows either due to bad optimisations.

Linux isn't difficult, it just takes some patience to learn. Most things now don't need command line interface to do, but it doesn't hurt to learn the basics.