Since nvidia drivers do not properly implement implicit sync, this protocol not existing is the root cause of flickering with nvidia graphics on Wayland. This MR being merged means that Wayland might finally be usable with nvidia graphics with the next driver release.
EDIT: Nvidia dev posted that support is planned in the 555 driver, with beta release planned for May 15: https://github.com/NVIDIA/egl-wayland/pull/104#issuecomment-2010292221
I’d argue the root cause was Nvidia insisting that X11 was the future, they’d never support Wayland, and refusing to participate in any of the design processes. As a result when they got dragged kicking and screaming into supporting Wayland, nothing that had been developed without Nvidia suited their hardware or drivers.
They first tried to throw their weight around by forcing EGLStreams on everyone, failed, and they’ve been scrambling to catch up ever since.