X has a singular fully functional implementation into which you can slot a wide variety of components. Because everything is a component that slots into the singular X implementation forking has both a low benefit and a high cost.
Wayland is just a protocol everyone must implement with a semi useless reference implementation that nobody would ever use. Nobody forks Wayland they just implement it as they must the X approach isn’t available.
It’s apples to oranges. A meaningless comparison. Its more just churn than innovation on the part of desktops.