what kind of content is monetizable exactly ?

When I use some stock footage I got instantly demonetized, so I guess the issue is not only copyrighted content, but anything that is not our complete own footage?

So I recently made ai footage to replace the stock one, and it got demonetized again for unoriginality, so I wonder what kind of content is monetizable, Is it only footage from our camera roll like talking to the camera ? can’t find the answer in the guidelines