Steam makes millions of dollars for Valve. They can afford to put a lot of work into making it impossible for anyone to ever catch up to them. If you will never use anything else until it has feature parity with steam as well as having other upsides compared to it, you are never going to benefit from the other upsides.
What upsides?
A. Many games that are DRM free on GOG are also DRM free on Steam.
B. Most of the games that are only DRM free on GOG are old, out of date builds that don’t get bug fixes and updates.
C. Even if both of those weren’t true, DRM free isn’t worth a terrible UX and no features. If GOG had feature parity for everything Steam does except big picture mode, big picture mode alone would outweigh the outrageously small chance that Steam somehow removes access to my games.
But they’re not just not at feature parity. They’re like 2 out of 10 software. Better than Epic’s 0 of 10, but still really bad.
Many games that are DRM free on GOG are also DRM free on Steam.
I challenge you to download an offline installer from Steam for these DRM-free games they host.
Why do you need an installer? Most of the games we’re talking about you can just run the executable and be fine, because those are the games actually willing to publish on GOG. The ones that are substantial enough to need an installer are the same ones I talk about in B, that don’t get basic patches and bug fixes, because GOG’s customer base isn’t worth the effort and GOG wouldn’t have the games at all if they required update parity.
But again, it’s completely irrelevant, because GOG and Galaxy don’t offer any of the features to manage a library I need. If Steam didn’t exist, I would abandon PC gaming entirely. No other platform on PC is anywhere near acceptable.