One of those features is Proton. Thanks to Steam I can play every game I am interested in, without the need to install Windows.
GoG sometimes pushes out Linux installers that they immediately stop supporting, resulting in non-working games. Fuck that.
I don't want to use Windows, but play on my Linux Gaming PC. This works really nice because of the work, Valve does on Proton and gives back to Wine. GoG is cool, but they don't help in regards to this. The Epic fucks (hehe) are actually hostile towards Linux, so before I would buy there, I would pirate their games or just not play the game at all.
When the Steam enshittification starts, I will be one of the first to say fuck them, too.