Why would it have to be KDE or XFCE? GNOME as it exists today is probably the closest to macOS' design language, and whatever you do designing any kind of operating system UI, macOS needs to be the benchmark. GNOME 2 in the olden days was my favorite DE so today I have to go for things like KDE or MATE but I'm not a novice and I can fully acknowledge that what works for me isn't what works for everyone. GNOME probably made the right decisions to lower the entry barrier towards Linux.
XFCE to me is purely a choice for outdated hardware so unless your extreme beginner has an extremely old PC XFCE is a non-starter. Whether KDE can be made more accessible to the non-initiated I can't say. Anything that has a Windows-esque taskbar is probably ill-equipped from the start as well. Again, macOS is as easy to use in a keyboard and mouse sense as tablets and smartphones are with our fingers. This is the way.