And the cool thing is, Proton (Windows to Linux compatibility layer) and FEX (x86 to ARM emulator) can be used without Steam. Even SteamOS can be used without Steam (although it is preinstalled, but you can boot into Desktop mode and use other stores instead). It's not just optional, its free of charge and Open Source and not locked to a specific eco system.
Just fangirling here. Sorry. :D