Frankly it's very weird that you've tried them with Lutris and Heroic and have such a horrible success rate on GOG games specifically

Oh it's not just GOG, it's Epic as well. And frankly, I don't believe you. Based on what you said above about "don't tend to learn how to do things yourself" I'm gonna guess you're using all sort of tricks to get shit to work. The only thing I do is hit download and then open. If they don't work, I don't bother with anything more than that (or try opening them in Steam, sometimes that works).

You must be incredibly unlucky or the Steam Deck (assuming that's what you use)

I have 3 different devices, including a Steam Deck, that I have had the same experience on.

Steam games come with phone-home DRM

Which is completely irrelevant if you're not buying/redeeming them on Steam.

GOG going with the Steam APIs and Steam's very own fork of Wine (which is what Proton is), the former designed to tie games down to Steam's server infrastructure

LOL what? I'm very interested to hear more about what you think Steam's "server infrastructure" or the store app has to do with this. And how that relates to myself and GOG having problems but you not having them? How can it work "just fine" for you in Heroic/Lutris but simultaneously GOG is incapable of the same?