I think non-programmer friendliness can wait till there are enough technical users that the superficial daily-experience bugs get ironed out, and also the newbies have a social support system for onboarding. Trying to jump that curve will prove painful in the long term.
I would love to see the guidance and tools for technical users to try this out and start switching over the next few years.
AFAIK, Gnome/KDE or some other DE can be built/installed like any other package, so one can certainly have pretty much any GUI, just like any other Linux distribution.
I’ve been using the NixOS container support which has drastically streamlined and unified the largely similar but many small variations of containers that I use https://nixos.org/nixos/manual/#ch-containers
At the moment neither have gui integration and unfortunately both could use a lot of work with onboarding and beginner (I'm taking non programmers) friendliness.
[0]: https://guix.gnu.org/manual/en/html_node/Invoking-guix-pack....