I have never used the Steam beta or Proton-GE or whatever information is spreading out there to noobs about what they should do, and I've been gaming exclusively on Linux for more than 20 years. Only do this beta or bleeding edge stuff if you have a problem, and a good reason to believe that will help (like people reporting your specific issue is fixed in beta). Or I guess if you're bored out of your mind. And expect other issues since it's fucking beta.
One thing often useful (particularly for older games) is support for more video codecs. Due to licensing, valves proton supports less video codecs, which can sometimes cause cutscenes to be played as test-images instead.
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.