I just don't see a Linux gaming machine being a reference piece of hardware for big name publishers when they are making Windows-only games.
The Steam Survey is a better indicator of what you should target vs. something like the Steam Machine or Deck IMO.
It's not about a consistent target like consoles and more that even older hardware performs acceptably with minor concessions to graphics these days. People were already primed to accept that trade off before the AI boom exploded memory prices because crypto miners were buying up loads of cards for alt coins that didn't have ASICs available.
I can get something like 80% of the graphics with 20% of the GPU because the places where games are really pushing graphics out now are really resource intensive. Ray tracing is amazing but we got REALLY REALLY good at making games look good without it too.