I dropped Steam because it gradually made the client less and less user-friendly. It’s bad enough that I kinda have to use the Steam client, but then they had to do things like trash the old rendering engine and replace it with the bloat of a browser, and completely discard List View (which GOG Galaxy has just fine) and replace it with a tile view that can’t even display game names in plaintext (which GOG Galaxy also has an option for in its tile view).
And that’s on top of other issues with the platform such as how the Steam client forces updates. (Sure there’s various workarounds but at that point Steam stops being a convenience anyway.)
I never actually needed a launcher client anyway. I gladly buy direct-download installers from sites like itch and Humble and DLsite. I don’t have a fear of command line interfaces, lol, much less simply using File Explorer as my launcher. I’ll use a platform’s launcher willingly if it just offers benefits, but the drawbacks of Steam’s using it as DRM eventually turned out to outweigh whatever minor benefits it presented.