ussnorway: Why = because Steam changed their code and it blocks Gog... we can debate if that was the intended result or just a happy side effect
what is happening = Gog stores your Steam username\ password in one location and Steam defaults to looking in a different one... the basic test for this is to play one of your linked Steam games from Galaxy and it will ask you to log in, even when Galaxy has your Steam account setting stored [sign in image]
your right panel of Galaxy shows Steam mates because it was coded correct [see friends image] but the left one was adjusted by Gog without testing so it does not work
side topic: your Steam Library settings are upto you mate... I personally don't think setting them to public is a great idea but that is not the reason things stopped working unless you want to sync owned games for one of the free store deals Gog put out from time to time i.e, 'get it free on Gog if you already own it on Steam' type deals
yeah I literally just learned about the GOG connect feature minutes ago, where you get to transfer a steam game to GOG, I'd love to do that. but I never did in the past I think because my stea account is private, which really sucks.
Thanks about the background. so Playnite keeps finding ways around steam's code to access your library with your credentials and Steam doesn't care, but they keep blocking GOG?