I don't really use Plasma itself (and soon i wont even be able to if the rumors of them dropping X11 support are to be believed) but i do use various KDE apps, like Krita (which i use for most painting stuff), Kate (my main programming editor, coupled with clangd for C/C++ programming), KolourPaint, Spectacle, Ghostwriter, etc and in general i find KDE/Qt apps to be more to my liking in their UX than anything based on Gtk (or at least Gtk3-or-later, Gtk2 stuff is for the most part fine).

They aren't dropping X11, they are only dropping it in their new login manager. Change the login manager and it will continue to work fine for now.