I've had the same issue since updating my OS and the steam launcher. The game, right up to endwalker, ran just fine before that. Right clicking the game in the steam library and adding PROTON_USE_WINED3D=1 %command% into the Launch Options box lets it launch and run, though is doesn't run well. It's an OS or Launcher update that likely did it.
Keeping in mind I am using the Linus steam app. But the launch command might work on windows as well? Unless getting a new monitor can mess anything up.