A UNIX graphical system without a proper developer stack, with frameworks for all layers, means everyone does their little thing, the people that can't be bothered just ship Electron or something just as bad, and for all user purposes to manage windows, and a couple of xterms, one could just be using FVWM from 1994.
Which is how I look to most of these new desktops.
Not only that. Those frameworks are constantly changing. Old APIs are left behind while new, incompatible APIs are introduced swiftly. Fortunately, the Linux desktop is now perfectly usable despite all this, because most software runs in a terminal, the Electron engine, or in the web browser.
Which is basically why nowadays, my devices don't run GNU/Linux.
I am old enough that when I reached university, there were still green and ambar terminals to a DG/UX server used as timesharing system by all students.
Electron, the only application I tolerate on my private computers is VSCode, mostly because some plugins aren't available anywhere else.
Browser, I can have anywhere.
If it is to have the same experience as early 1990's UNIX, I can just as well ssh into a server box, VM or container.
Isn't this what Gnome/Libadwaita is trying to solve? They've been putting quite a bit of effort into it, and gnome builder, flatpak & related tech to have a proper developer stack for making GUI apps, and a community (gnome circle) to show them off.
At one time Gnome ejected a portion of its user base in order to become something that would work on tablets and phones as well as desktops - at least that seemed like the rationale. At that time it looked like there might be a market for linux devices with a UI and I don't know for sure but I think some money was spent to achieve this which is why objections by users were of so little importance.
Nowadays phones seem like a duopoly that cannot be challenged and tablets aren't very important anymore. Linux doesn't matter on the desktop because browsers are the UI and the apps run in the cloud. The whole GNOME/KDE/whatever effort is a bit moot.
Yes, both GNOME and KDE, but unfortunately never took off as many of us expected in the 2000's, and nowadays apparently tiling managers without such frameworks is what is cool.
Which is how I look to most of these new desktops.