Looking at a screenshot from KDE home page, it really does not seem like anything has changed with it in terms of design polish that much. It doesn't even seem like it's moving in a direction that's any different. https://kde.org/announcements/plasma/6/6.4.0/fullscreen_with... The most significant change for the whole look they could make is changing the system font, because that's the biggest and most visible thing, and the one they have looks amateurish and makes it feel slapdash, like it was an afterthought, just picking whatever default font there was and going "whatever", which kind of ends up being the vibe of the whole thing.

So you don't like it, I'm so sorry. I think it's a cluttered terrible screenshot, and I think KDE looks more consistent than Win11 or macOS.

Nate's blog is full of detailed, significant, careful improvements to KDE's UX over the past few years.

If you want to change the system font you can go right ahead. Don't knock it for it's default appearance because everything can be changed and skinned. Some people have made it look just like Windows, others just like macos.