A crucial distinction. If one does not charge anything, Drive thru does not give you the same benefits as a paid publisher. Stock art might seem a bit cheesy, to even with a bulk subscription, it is $2-4 per pic. Affinity is cheap, and a good value in general, probably like to have photo, and designer w/o being a publisher. I am old school and like to have physical books too, hard bound is nice because they lay open on the table. A lot of other costs in there as well.... a publisher trying to make money.
The IP, copyright, trademark discussion is for someplace else.