I don't really see the parallels.
For the past few months I've been investigating and working on porting parts of Xfce to be usable under Wayland. It's astonishing the number of features that are just not implementable at all on Wayland, at least not without inventing new non-standard Wayland protocols. (Another option is refactoring the desktop environment so all the individual components run in the same process as the compositor, and have access to the compositor's internals, but that's unacceptable for what are hopefully obvious reasons.)
Even after over a decade, Wayland still seems quite immature and poorly thought-through. The protocol standardization seems geared toward satisfying GNOME's use-cases and ignoring everyone else's. The wlroots camp has gone their own way on a bunch of things, which is fine, but fractures the landscape a bit.
Making Xfce fully Wayland means turning the window manager, xfwm4, into a Wayland compositor. For someone already familiar with xfwm4's code base, that's a year or more of work (and a requirement we'd have is that it would have to support both X11 and Wayland, further complicating things).
Even if fixing inherent problems in X11 (security, graphics rendering, etc.) would require compatibility breaks, personally I would find that preferable to throwing the entire thing out and having to build (and build on) an entirely new system. As much as I disagree with JWZ's attitude on a lot of things, his description of most open source projects as a "Cascade of Attention-Deficit Teenagers" seems to be pretty accurate, at least here. X11 hasn't been improved and fixed because no one wants to maintain and improve X.org anymore, and the people who used to maintain it would prefer the fun of chasing and working on new shiny things, even if it means decades of new make-work for anyone working in the Linux GUI space.
Don't get me wrong, I am the first one to cut off anyone at the knees who feels they are entitled to tell open source developers what to do with their time (though it gets a bit more complicated when many of those developers are employed by corporations to do this work). But I think it's pretty shitty to push the desktop in this direction and essentially force desktop and toolkit and application developers to choose between stepping up to maintain and build on X.org (something well out of most people's wheelhouse), or spend a huge amount of time porting to a new display system.
Having said that, Wayland does have promise to be a better system than X11, even though it will likely take another decade to achieve feature parity with what we already have. So I'll continue to work on getting there eventually, even though I resent the fact that I have to learn an entirely new display system so I can work on reimplementing the same features again instead of building new features, fixing bugs, and making things more polished.