Linux is all good if you only play singleplayer games. My friends started playing the finals yesterday and it doesn’t run on linux because of EAC. Windows can run all my games without any proton switching and all the nvidia features like ray reconstruction and pathtracing with frame generation just works (alan wake 2 looks so good).
Valve does, and they were instrumental in getting EAC support. But they can’t force them to do anything, they can merely bait them with Steam Deck and desktop users, and those stats are all available in their surveys.
If a dev asks Valve for help with Linux compat, I’m sure they’d help.