I also use KDE because I like customizing my DE, but I’m not sure I agree that it’s hard to break. When I just switched from Xfce to KDE I downloaded several global themes using the built-it theme browser, and a few of those definitely messed things up. It’s also happened more than once that I boot my computer and end up with only the desktop background (i.e. no panels or context menu) because KDE thought there was some wrong with the theme, which can be difficult to recover from for someone who doesn’t know how to ctrl-alt-F3 and edit settings manually. Though it’s ofc. more stable when not testing global themes, and only changing other appearance settings.