Apart from this being increasingly false (wayland being the default display server for gnome since more than 2 years now), adoption rate is much more correlated

Apart from this being increasingly false (wayland being the default display server for gnome since more than 2 years now), adoption rate is much more correlated to the importance of the component than with the quality of the tool, just look at the history of ipv6. The more a component is part of a low-level core, the longer it will take to replace it with anything. Inertia.