After being a GNOME user for nearly 20 years, I decided to go all-in with KDE Plasma, and see what it was like.
I had found previous KDE versions confusing and ugly. So far, the Plasma desktop is very nice! One thing I really enjoy, is the default settings and appearance are intuitive and attractive. BUT... if you don't like something, there are options to change nearly everything. GNOME's simplicity is nice, but over the last few years found myself using the native GNOME applications less and less due to missing options. And I'm not a big fan of how GNOME 40 is even closer to Mac OS 11.
I have swapped the vast majority of my GTK programs for QT equivalents. GNOME Boxes is the only one I haven't found an alternative for. I was using it as a manager for a number of SSH sessions, and still haven't found an alternative.