I wish I liked GOG, but they ignore Linux users, while Steam's Linux support is the best thing that's happened to Linux gaming.
It's probably outside their scope, and they are not as large and wealthy as Valve that they can afford to invest the necessary resources. But you can use 3rd party launchers like "Heroic" that support GOG and basically give you the same experience as Steam does.
On my homemade NixOS SteamOS-like gaming box, I have it boot into the SteamOS interface, and it's pretty and console-like, and it's nice to be able to quickly install my GOG and Epic games and automatically add it to Steam so it can be easily played with that interface.