Hello @dirkmittler, most Linux computers that have Steam installed don't have hardware or drivers that can deliver Vulkan 1.3, this is based on a false assumption. You can have hardware from the last decade running Linux with drivers that provide Vulkan 1.3.
Regarding VKD3D-Proton's requirements, that should be directed at the subproject, but in general, baseline requirements get raised when supporting the older spec universally harms performance on all hardware.
proton 8.0x1 2025-06
All versions of Proton greater than 7.0-6 require Vulkan 1.3. However, most Linux computers that have Steam installed don't have hardware or drivers that can deliver Vulkan 1.3.
What seems to have happened is that every time a game dev has come up with a little trick to prevent their game from running under Proton, they have successfully gotten Proton devs to bump up the latest Proton version, just to bypass that little trick in the design of the game. These updates to Proton don't seem to be graphics-related.
Also, nobody has ever explained to me why it was unacceptable to emulate DirectX 12 using Vulkan 1.2 as a back-end.
So, because most Windows games on Steam would now require Proton 8.0+ to run under Linux, I suppose that the devs have successfully made Proton irrelevant.
Sincerely,
Dirk