They went way too far with the corner radii and pill shapes imo, looks like a Fisher Price toy. Some inner buttons retained the old radii and don't match the outer window radii anymore.
"right angled corners again"
I have a feeling you aren't and haven't been a Mac user for a long time. When was the last time Macs had right angled corners!? 30+ years ago?
I’m not a fan of Windows but I believe that probably the best modern UI design system for desktops right now is probably the flavor of Fluent used in Windows 11. It still retains somewhat desktop-like information density, doesn’t go overboard on radii, and has a touch of depth. I’d like to see more design languages exploring in its general direction.
Apple still has the best "get out of the way, be invisible" UI.
Both are valid ways to approach to a problem, but I like KDE's batteries included, infinitely customizable way better.
I don't customize it heavily either. Move tray, clock and menus to the top, a-la GNOME2, leave taskbar at the bottom, both auto-hidden and narrower than screen.
Add four desktops as a 2x2 grid, re-enable old CTRL+ALT+$ARROW keyboard shortcuts, add a couple of usability effects with custom key combinations and two active corners, and I'm done.
Some applications (Konsole, KATE) get custom fonts and themes, but everything else is bog standard. Setting it up takes 30-ish minutes, and it's the same config for decades now. Probably because of sharpening the same tool and optimizing without knowing.
Then, I can just concentrate and fly on that environment.
Also, they have improved a lot in the small areas where it was lacking. You can use your system without a terminal if you want, plus Baloo works really well.
The only missing piece is "global menu bar" and full-screen applications.
Since I don't use KDE on a mobile system, I don't know how well multi-touch trackpad works, but the rest is almost there.
As I said that I neither need or desire to go that far (my custom layout works like a charm for me more than ~15 years now), but it's not off the left field for KDE.
I guess it still can be done.
How mouse/keys/scrolling behaves, what pointing devices do in what cases are easy cases for KDE. Notification system is also pretty powerful.
The reality is, everything is cross-pollinating from each other. Even if making pixel-perfect copies is not possible, both are pretty interchangeable.
I use both Macs and KDE for more than 15 years now, and can switch from one to other instantly. Both are in front of me during a normal workday, and I just switch without thinking.