Corel Linux first launched in 1999, from the same company that at the time owned the WordPerfect word processing software. While it was made to compete with Microsoft's Windows it quickly died off.
KDE can look like pretty much anything. The default layout is generally Windows like with a lower panel with a menu and task bar to the left and a system tray to the right.
Windows 11s big "innovation" is centring the task bar and start menu. In the latest version of windows 11 you can finally move it back to the left. KDE can already centre both or move to the left and much more. There are also windows 11 global themes in the KDE library, I've not tried them though.
Windows 11 is otherwise not that different from windows 10. KDE already has all the graphical bells and whistles, and has long had a unified settings menu, and has way more flexibility for changing up the layout (it can be Mac like or old gnome like, or gnome 3 like or custom).
A lot of the gnome 2 based WMs are also very flexible - xfce, cinnamon, etc. I've never used Gnome 3 - I assume it's similar?
Xfce isn't based on GNOME at all and Cinnamon is based on modern GNOME, not GNOME 2. Mate is based on GNOME 2, tho. All of them are very different from modern GNOME, tho.
MATE is a continuation of the GNOME 2 code after GNOME 3 came out. It literally IS GNOME 2 just with a different name.
Cinnamon was also a reaction to GNOME 3 but it is an alternative desktop for GNOME 3 ( and newer ). It is mostly modern GNOME. It was never based on GNOME 2.
The only thing XFCE has in common with GNOME is that they both use GTK. XFCE was originally based on XForms ( the XF in XFCE ). It certainly has nothing to do with GNOME 2.