I’m looking for something simple that just works, with few crashes, few bugs and good community support. I’m moving away from Manjaro Cinnamon unstable branch to Ubuntu 20.04 and want a stable desktop environment. I only want bleeding edge software, but I want a stable foundation.
Xfce does not get updated often, so by that definition it is the most stable.
It’s also pretty stable from the perspective of not crashing, but I can’t say I’ve had much trouble with KDE either.
Xfce is rock solid.