I've been gaming on Linux for a year now and I have (and run) way more games from GOG than Steam.
Historically I avoided Steam because of the whole "you don't own the games, you just license them at full price" nature of the "phone home" validation they have for most games, so I had a much larger collection in GOG than Steam to begin with since I would only get from Steam the really interesting games which I wouldn't find in GOG (plenty of games I simply did not buy because they were Steam only).
That said, running GOG games in Linux is as least as simple as Steam games, thanks to me using Lutris which does all the heavy lifting of properly configuring Wine and VKDX to run my games and even integrates with GOG to directly download the installers: in practice I have about the same chance of success with click-and-play installing and running a game in Linux from the Steam Store via the Steam App as I do from GOG via Lutris.
Then on top of that, because I'm a techie, I actually prefer Lutris + Wine because it's so much more open for configuration than Steam and to figure out yourself how to run games for which there are no pre-made configuration scripts, such as pirated ones - for example, for one of my Steam games I couldn't at all find a way to run the official version of the game in Linux via the Steam App, but I could get the pirated version of that game to run just fine via Lutris.
I even have a default setting in Lutris which will run my games inside a Firejail sandbox with networking disabled plus a bunch of other security settings, something I can't do in Steam (were I can only do it for the entire Steam App, which won't function with disabled networking).