I still Wayland is a titanic mistake and that X could have been extended indefinitely instead without a flag day, without weird breakages, and without any loss of core features.
With a load of backwards compatibility for devices that don't make sense for a normal usage and patches for patches that were written fix bugs which were written to extend X. Better to start from scratch IMO.
I don't see the backward compatibility burden being very high. The core protocol just keeps working.
Microsoft spends millions for backward compatibility and they charge a fortune for that. This is an open source project with not as much resources and the core protocol of X was never made for GUI. It was made for displaying a cute clock on the screen when there was no concept of GUI. They extended it to do something it was never meant to do.