I’m just a Haiku user, however looks like AMD is trying to refactor Mesa interaction with the Linux Kernel:
https://lists.freedesktop.org/archives/dri-devel/2021-April/303671.html
The discussion is intense and touch: performance, security, why only Wayland approach (BSD, android excluded), VR headsets, browsers, why relay on Linux’s ABI api and so on.
Very complex and a good reference point when a new user makes a complaint about why Haiku lacks GPU acceleration.
Even with all the money and resources, Amd & Intel developers have a difficult task making their drivers faster on Mesa.