The common gaming-focused Wine/Proton builds can also use esync (eventfd-based synchronization). IIRC, it doesn't need a patched kernel.
The point being that these massive speed gains will probably not be seen by most people as you suggest, because most Linux gamers already have access to either esync or fsync.
Maybe you are right about esync but anyway I would also gather a lot of people don’t have that either. At least personally I don’t bother with custom proton builds or whatever so if Valve didn’t enable that on their build then I don’t have it.
> if Valve didn’t enable that on their build then I don’t have it.
The Proton build is Valve's build. It supports both fsync and esync, the latter of which does not require a kernel patch. If you're gaming on Linux with Steam, you're probably already using it.
