was just a quick question – on the GTK side of things, we have the progression of LXDE → XFCE → Gnome – but on the Qt side of things, with LXQT → ??? → Plasma, there’s kind of a missing middle option?
I don't know how active it is anymore and how stable on Desktop, but maybe Lomiri?
Deepin also seems similar, in that it seems to sit between the two, but I can't recommend that due to the persistent disregard of security issues re that DE.
Lumina was something a bit similar to XFCE in that it seemed to want a simple stable base and ui, with only key technologies updated, and lots of options. Looks dead though now, which is a shame as I enjoyed using it for BSDs.
I think no other Qt baded, Wayland-capable DE exists, and thats probably okay.
I see though, how buggy and complex KDE sometimes is. KDE 6.0 will be more streamlined and unified, and I think on that base it cooould make sense to remove components, slim it down more, maybe prefer some resource saving Apps over others, and you are good to go.
At the same time I have no idea what apps should be replaced, as KDEs are very good. And with Trinity, based on some outdated version of KDE, I dont think you will get a good experience.