Any improvements to ‘SteamOS’ extend through to Steam on Linux and Linux compatibility in general. Proton has made huge leaps in the last two years alone, so much that day one AAA releases sometimes even run better in Linux than they do on Windows. Proton is good for running Windows applications in general, too, as the improvements benefit Wine users. There’s some sites that guide how to set up normally problematic apps when in Wine but using them with Proton instead.