I started dual booting Linux back when Steam for Linux was reasonably new and Portal 2’s native port was on beta. Briefly went back to Windows after building a new, much powerful system for about a year, DXVK & later on Proton happened, and now all the games I care about work flawlessly.
There have been games on my Steam library that I never ran on Windows despite them not officially supporting Linux.
With the deck I seriously hope devs slowly but surely start thinking about native ports as well, but I won’t mind waiting another - uhh, 10?! - years for that to happen. I expect Steam Linux Runtime & Flatpak to be the DXVK & Proton of native ports - as in, the thing that will make them “viable” instead of “theoretically possible”. Win32 is still the most stable ABI on Linux after all.