The Wayland protocol is fine and provides the modern features expected (“every frame is perfect”).

But X is two things: a protocol and a de facto standard server that window managers could easily interface with.

I wonder if we’d be in a different place if Wayland as well as offering the protocol also offered a de facto standard server (not simply a reference implementation in weston) with a window manager protocol that more or less forwards on client <-> server messages that a window manager would care about. Client buffers shared with the server can also be shared with the (separate) window manager process which then shares its composited buffer with the server for final rendering.