

Windows 10 wasn’t even on my list as it is not a modern OS any more (it has been replaced by Windows 11), but even so it had a better UI, without those weird UI features that just serve to look bad
- floating taskbar at the bottom, not actually at the bottom, above it
- those blue highlights around widgets that do not look good
- that horrible off white colour for widgets
- general bad design
And of course windows 11 and GNOME improve with even more UI features
- blur
- transparency that actually looks good
- rounded corners that look good
Basically, it’s not one specific thing that makes KDE look bad, but rather their general approach to design, which seems to be ‘we don’t care what we’re doing, we’ll just set the default to something random as we expect users to customise it anyway’ which is fine for advanced users, but not so friendly to new users
I’ve experienced that with a variety of words at different times, I’ve heard it called semantic satiation, but also that that actually doesn’t mean this, but when no words make sense to you, not just a specific one.