There are definitely some cool features missing, but I'd take KDE over any other window manager without a second thought if it were possible.

I’ve found the downgrade surprisingly minimal on plasma 6 - and it’s far more customizable.

Thanks to marginal gains on MacOs (nee OS X) the Linux desktop gets closer more quickly than Apple can pull away.

What downgrade? A typical Gnome desktop is far more coherent than Windows or even macOS in some regards these days.

Yes, and you can do much better than GNOME, too.

Yes I use cosmic DE on Fedora. I didn't find it a downgrade at all! Despite not running an M chip it is butter smooth