A question with no right answer, because it is a matter of taste and habits.
Both are very much sophisticated desktop environments which very useful defaults. Neither Gnome nor Plasma are too complicated for beginners and can be customized easily. If you want to you can go very deep into the customization too.
When I am on Hyprland I use foot. It is fast and well configurable.
My fallback is Gnome and inside I use the new kgx aka Console. I like that it shows in the window decoration's color when I'm working remotely or as super user.
Using NixOS as my daily OS on a X1 since six years now.
The first months have been hard as at this time was no installer at all and I had to do everything manually. After a while I got used to the update process.
Recently I switched to Nix Flakes which is another challenge but seems to make the Nix way even more consequent.
The only odd thing what drives me nerves is that compiling on that machine takes sometimes a half day.
You seem to be aware of many things.
Just for communication you are using more unfree tools then free and more then in the other categories.