I mean you can do that now. * Install the OS of your choice. I would recommend Nobara for minimal tweaking for games. PopOS is another popular choice * Instal

I mean you can do that now. * Install the OS of your choice. I would recommend Nobara for minimal tweaking for games. PopOS is another popular choice * Install steam and enable proton for all games in Settings * If you want Steam desktop UI, you can opt into the Steam Beta, set Steam to load on boot with launch option '-gamepadui' and voilà! You have yourself a Steam Deck gaming desktop!