good is the enemy of excellent. X11 works for most users (almost all the users?) well. You can see that with the adoptions of other standards like the C++ standards and IPV6 which can feel like forever.
Another thing I think one of the X11 maintainers mentioned iirc is that they have been fairly gentle with deprecation. some commercial company could have deprecated X11 and left you with a wayland session that is inferior in some ways.
There is a fairly active fork already . We well see what he will do. AMD saying it is not legally binding despite him signing a contract sounds like BS. Consulting the software freedom law center or some other non profit might be worth while.
Growth have been fairly organic . number of contributors grew by 28 percent this year. there are a lot of users so given that a percent of them will do some form of advocacy that will probably lead to more users and there will be a relatively large amount of people saying they adopted it.