It can be, but it depends on how dependent one is on various applications and sources. I'm in the process of doing such a thing, but I'm taking the slow route so I don't break everything. Meaning I'm moving one thing at a time off Snap, and then I'll be closer to a Debian/Mint DE version in the switch over than if I did it right away with so much tied to it being Ubuntu.

For a casual user it may not be that dramatic and just a matter of moving data and learning a new desktop look. I'd still suggest the Debian version of Mint over Debian if they went to Ubuntu for the easy use.