That might not seem like a big deal, but if the goal is to get as many people switched away from commercial operating systems as possible there needs to be a healthy range of conventions/workflows represented by meaningfully different DEs so more users find one they can slip on like a comfy pair of shoes. For most people, switching desktop paradigms is something they want to avoid if at all possible because of the immense friction it brings.
Still alive and being maintained, too.
Xfce has a plugin to do it as well, but it needs various strange Gtk settings to tell apps to use it, and I can't get most of those to work.
There are some impressive KDE-based distros out there, and I wish someone rose to the challenge of offering a Mac/Unity-like Xfce-based desktop.
Then the gnome 3 team intentionally sabotaged it all by intentionally arranging for gnome 3 apps to refuse to coexist with a gnome 2 install.
Sigh.
XFCE are not that far along, but the developers are tinkering: https://www.phoronix.com/news/xfwm4-wayland-May-2023
Also I disagree about it being unproductive. Not everyone is most productive in i3 or whatever.