GloriousEggroll among a few others, and Valve of course, are the main reasons Linux gaming is now effectively solved (aside from anti-cheats where there’s nothing to do if some developers don’t want to support Linux).
I haven’t yet watched the video, but I agree I’ve not needed to use Steam beta at all. While it’s around 70% of tracked games being labeled Gold or higher on protondb, I have found that with proton-ge, 100% of the games I’ve tried have worked without issue (on the order of 30ish games thus far).
I won’t be going back to Windows, ever. So it kinda stinks that some devs just won’t support Linux for anti-cheat (like Lost Ark, etc). But it’s a price I’m willing to pay to not be spied on.