When you use XFCE, the underpinning involves a lot of Gnome programs. The Gnome desktop seems awkward to me.
I also use XFCE (on Debian).
Gnome is sluggish even with plenty of RAM and a quick processor. And it’s “minimal” interface really is not intuitive.
KBE might be good, or not, but I really don’t care. I just want to use my computer. I don’t want a “desktop”.
With the libraries installed you can still use any application you need. I use FreeCAD a lot and it uses KBE for it’s UI and it is fine. I also use some Gnome based apps.