It has a really great selection of polished layouts OOTB that can make GNOME look very familiar to whatever the user is used to.
Also has some other great tweaks around WINE for beginners, and a more easily accessible Nvidia option in install media.
I don’t use it myself, but I would suggest it is ideal for someone who is a basic computer user who wants to mostly web browse and use home office tools. It really is ultra-polished.
Yes this could mostly be replicated with extensions and themes, but honestly, unless you have strong feelings about your OS, which most people don’t, it is not worth messing about with this (particularly when installing for others) when Zorin is available; it can be a headache to have to maintain such comprehensive layout changes through extensions and themes without breakage throughout upgrades. It also has the benefits of being based on the very actively developed GNOME, compared to something with a smaller team like Cinnamon, namely much better Wayland support, and in my view more polish.