I wanna throw in KDE connect too, honestly, the best and easiest way to work with an android device from a PC hands down.
On the other hand, XFCE is much more approachable and usable for a newcomer. It's not intimidating. It's not infinite. It's more resource friendly and straightforward. For a newcomer I recommend GNOME or XFCE. When they're seasoned enough, they automatically gravitate towards KDE most of the time.
Not any more since the switch to GTK3. Plasma is more lightweight since than.
I like to use different things. Keeps my mind open.
For those still burning plastics I would add K3b to the list.
I am using Gnome since 2018 btw.
So C camp went with GNOME, and C++ camp with KDE.
Naturally then GNOME got bindings for C++ (actually quite good), however it is a big difference being the main language or one that always needs someone to write bindings.
Desktop effects are not gimmicky but useful (e.g: dim inactive windows). Power management makes sense and is reliable.
KDE can behave like anything you like and doesn't bury power-user related features somewhere. It's all visible. Multi-speaker & multi sound card management is also better, more obvious.
I'm using KDE since 3.5.x including 4.0 release train. Its infinitely better. Stable, fast, extensible and infinitely useful (esp. Dolphin's services).
I'm not using too many widgets and/or activities, but it's better than anything I use (incl. macOS, albeit they're close).
KDE is rock stable in my experience. Runs for weeks or sometimes even month (between kernel update reboots) without any crash or this like.
I'm running Debian Testing. So it's usually not the newest release of the desktop. I guess this makes it so rock solid for me.
Anecdotical story regarding stability of a DE: I had to use Windows 10 lately. I think the compositor crashes quite often if one has to may open windows. :-D