James,
I was having the exact same issue. In fact, I found your post when I was trying to fix the same issue. The game was working on Linux mint 20.3. I got a new HD so I did a fresh install Mint 21.1 and of steam. Then I was getting the exact same error as you. I did two things to correct the issue. First I installed the Microsoft runtime files for Linux (which I don't think did anything to fix the problem). I rolled back my Nvidia drivers from 5.35 back to 5.25. Running "Driver Manager" in Mint is a very easy way to roll back proprietary drivers. I also uninstalled the game, browsed to the game directory and deleted the left over scripts too (Not sure this did much). Reinstalled the game with Proton Experimental and after that the game works flawlessly, without any of the launch options (though I did wind up using --skip-launcher because launchers are pointless).
I BELIEVE that the issue has to do with the game trying to use older versions of the Vulkan drivers than the Nvidia driver is trying to use. There is probably a way to force the game to use the right Nvidia-centric drivers, but this was the easier fix. I hope it helps.
