An antidote on non desktop use of X: the other day I wanted to show a program on my phone, there are many good ways to do this, but I picked none of them. Instead I had just installed a terminal on the phone and noticed they had an X11 package, So A few minutes later I was the proud owner of an X server on a phone. And you know what... It was pretty great. My gaming system load and temps dashboard were displaying just fine.
Despite using X for many, many years, I had never just sat down and played with a bare X server, I had only dealt with it through the lens of a locked down, encumbered desktop system. It was like having a network attached monitor. From whatever system I was using as a desktop system I could just go "display this on that monitor", in this case a phone. Based on that experience I put a raspberry pi on my TV running a bare unprotected X server because having a network attached monitor rocks.
The main mistake FD.o made is that they didn't get consensus on a "Desktop Profile" extension, so all the DEs wound up implementing their own thing. This is still fixable, just very annoying until we have agreement on this shit. I think that's what you meant by "feature parity with X".
[0] Currently, every desktop VR setup has to have two layers of compositors. VR applications have to communicate with a special VR compositor that then draws normal desktop windows with the contents of what should be hitting each eye of the VR display, all so it can pretend to be two normal displays.