In the book "Introduction to Electrodynamics, 4th edition" by Griffiths, the author says, I quote from page 278 :
(...) We call it a "bound" current to remind ourselves that every charge is attached to a particular atom, but it's a perfectly genuine current, and it produces a magnetic field in the same way any other current does. (...)
Basically what he explains in that section is that the magnetic dipole moment of every electron in a magnetized material contribute to an overall surface current (much like the rollers in a conveyor belt) and it is this current that produces the magnetic field around the material.
It seems to me however that these surface currents are not brought up in most descriptions of magnets. For example, in this video :
it is explained that the magnetic field produced by a magnet is a quantum phenomena that arises because electrons have a quantum property called intrinsic magnetic moment.
Question : Are these surface currents really genuine currents? Do we have any evidence for their existence? Or is it just a model that is used in calculations but does not reflect reality?