mqstout: You may have missed my point: Allow developers the "ease" of writing to a tight API code like Galaxy. Galaxy API should have built in automatic, unauthenticated, "VPN" connectivity for the LAN fall-back. This future-proofs things since, when Galaxy goes away, it's writing a single replacement to handle a ton of games.
Would I, personally, like games directly to support LAN built in? Absolutely. But asking developers to implement a bunch of different networking schemes is indeed a high ask. Which is why I wish Galaxy's netcode had been properly designed.
No, I am not missing it, I just don't think you thought it through. The one big question is: What for? What's the advantage?
You have an authentification and after that you are anonymus ... just for the sake of it? You are already signed in to begin with so you won't lose anything if that information is used. Or better: You don't gain anything by ignoring it.
But let's say we keep it this way. Because nothing can be connected to the user, there must be a different way to select servers and all that sutff you want. Two options: Either they create their own UI for it or GOG provides one, which then they must support, maybe via overlay? It would still have to be programmed custom for GOG, since other platforms like Steam, PSN, XBL and EOS don't have it, just replacing the DLL with the network interface would not cut ir.
And then of cource people would still complain about it being DRMed, because you need to log in to Galaxy. If you really want something anonymous, there must be no user of any kind. No login, no cookie, no anything. And it means more work.
Why would anyone want go through all that trouble for so little gain?