One of the specific issues from those who've worked with Wayland and is echoed here in Nate's other post that you mentioned.
Wayland has not been without its problems, it’s true. Because it was invented by shell-shocked X developers, in my opinion it went too far in the other direction.
I tend to disagree. Had say the XDG stuff been specified in protocol, implementation of handlers for some of that XDG stuff would have been required in things that honestly wouldn't have needed them. I don't think infotainment systems need a concept of copy/paste but having to write:
Is really missing the point of starting fresh, is bytes in the binary that didn't need to be there, and while my example is pretty minimal for shits and giggles IRL would have been a great way to introduce "randomness" and "breakage" for those just wanting to ignore this entire aspect.
But one of those agree to disagree. I think the level of hands off Wayland went was the correct amount. And now that we have things like wlroots even better, because if want to start there you can now start there and add what you need. XDG is XDG and if that's what you want, you can have it. But if you want your own way (because eff working nicely with GNOME and KDE, if that's your cup of tea) you've got all the rope in the world you will ever need.
I get what Nate is saying, but things like XDG are just what happened with ICCCM. And when Wayland came in super lightweight, it allowed the inevitably of XDG to have lots of room to specify. ICCCM had to contort to fit around X. I don't know, but the way I like to think about it is like unsalted butter. Yes, my potato is likely going to need salt and butter. But I like unsalted butter because then if I want a pretty light salt potato, I'm not stuck with starting from salted butter's level of salt.