What kinds of bugs are you talking about? I think part of the problem with KDE is that it's large enough that two users might be using completely different parts of it---I find that it's far more stable than GNOME, for instance. I'm not a fan of how its compositor makes scrolling look (I much prefer how Sway or even Windows does it) or how the compositor interacts with SDL applications, but that's not exactly a "bug".

Can you expand on what's not working for you? I use KDE via Kubuntu and have found it very stable. The only quirks are desktop environment things that I don't think XFCE even does OOTB, like sometimes it fails to auto-connect bluetooth speakers. The graphics stuff seems totally solid.

A good user interface is one you don't realize you're using. KDE is flexible enough to fit many workflows and doesn't (try to) constantly get in your way.

Its probably selection bias.

I liked KDE but it was too complicated for my use case. In general I have found that the fewer features a desktop environment has the more I enjoy using it.

I’m surprised that the logical minded folk of HN aren’t more geared to minimalist environments like simple window managers. If you’re an engineer why do you need or want a fully fledged desktop environment? I stopped using KDE after I discovered all I needed was a window manager and application launcher.