Isn't Debian an easy distro? I don't get it. Debian defaults to GNOME, setup is easier than Windows, includes a software store etc. what else do people need?
Why do you say that? It defaults to GNOME, that essentially had everything out of the box that those ones you speak about have. GNOME's default theme is also finally something decent.
I'm not saying GNOME is perfect, far from it, but at least they're no longer using brown+orange as their default colors. Now lets see if they can fix the font rendering once and for all.
I think Zorin's approach makes sense for people who don't want to learn a new interface and don't have a lot of technical experience. GNOME does generally already have a good interface, but I think a lot of non-technical people wouldn't understand (or want to understand) stuff like shell extensions and GNOME tweaks.
I don't think I would switch to it anytime soon, but I could imagine it being used in a university.
I think Debian is close to new user friendly IF they pick Gnome or KDE with all the default stuff there, and has getting closer with non-free firmware enabled by default now, but still isn't quite there as a plug and play new user friendly distro. Things like flatpak w/flathub or snap out of the box isn't there, and it'd be hard to get a full Debian setup without using the command line (especially for a non free software zelot who wants Spotify and discord out of the box)
Something like mint is just a tad easier, and that might be the different between an easy install and an unexpected set of hiccups that a new user might struggle with. The mint installer is also a lot more intuitive, at the cost of being less universally compatible (a big goal of Debian).
it's even more "easy" in it's presentation, the visuals are polished, it has a full windows like start menu, both on gnome and xfce, the theme config is clean and barebones, the choice of desktop configs with the bars and menu is reduced to like 6 choices, and little details like that to make it feel like a professionally made os, meaning it's only use is for people with no idea of what and os is, it's a little better at that than even mint, it does make it pretty shitty if you want to learn to use linux since many layers of simplicity are added on top of an otherwise full featured desktop