dylerius: -What can I do if a game is on Steam but not on GoG?
I am going to say something extremely controversial here, so maybe my advice here's going to get shot down...
... But check if game you want to play is being offered by Xbox Game Pass for PC right now.
I hate subscription services, trust me, but I think it'd be better to pay Microsoft 5 bucks for a month or two until you beat the game you want to play and unsub right after than to pay Steam or Epic $20-60 for a recent game.
Case in point, if you want to play Outer Worlds, I think it's much better to pay Microsoft the $5 than to give Epic $60; just make sure to buy the full game on GOG when it gets 'ported'. I see Game Pass as a rental service, and based on my mental gymnastics, I think it's MOSTLY harmless to support that service. If it were a streaming service though, it'd be a different thing entirely. Anyway, Game Pass doesn't have THAT many games yet, but still... Check that first, is my advice. Just turn off auto-pay and only pay the $5 when there really is a game you can't live without.
With that said,it's just video games at the end of the day and if you REALLY want to play something and don't want to wait 5 years, go ahead and buy it. Don't even feel (too) guilty about it, you have a limited time on earth, so you should play whatever you want whenever you want. BUT if you are like most of us here and miss the good ol' days, it'd be great if you mostly stick to GOG. There's countless great games here if you're up to read some manuals.
Personally, I just don't even look at Steam or Epic. Again, too many games on GOG I want to beat. Once I am done with all those, THEN I'll check out the other stores.