This is quite old. I think Amarok's Qt5 port didn't get finished, and I think Elisa is the new KDE music player:

https://invent.kde.org/multimedia/elisa

Also CD Burning? I think even in 2017 PCs and Laptops didn't come with CD drives.

Personally, I like KDE for the small touches. Like the file browser having an integrated terminal that follows the directories you're browsing.

If you want to see what the KDE's Design Guidelines are look here:

https://develop.kde.org/hig/

And GNOME's is here:

https://developer.gnome.org/hig/stable/

Perhaps it's worth doing a 2021 comparison?