[NegatioN]

Not a perfect solution, but you could just use Steam to load games from GOG on Linux though. Thereby getting "the best of both worlds". I have yet to stumble upon any major issue doing this.

[the_snooze]

Also, running other store launchers under Steam Proton works surprisingly well. I've been able to install Battle.net as a custom entry in Steam and run StarCraft II flawlessly in Linux.

[ktallett]

There is a gog galaxy Linux replacement called MiniGalaxy

[MaxBarraclough]

What does Steam bring to the table here?

[NegatioN]

You get to launch Windows games through Steam Proton. It's a no-hassle way to get up and running with gaming on Linux, although many are probably using Wine or Lutrix.