Part of your confusion, I think, stems from two uses of the word “artist.” Many people (like me) think of “artist” as a job description – someone who produces art. If you’ve painted a picture or taken a photograph or written poetry you’re an artist. Not necessarily a good one.
Some people, however, consider “artist” an honorific, a description to be reserved only for people who generate creative works that reach the elevated status of “art,” so one can paint portraits or draw American scenes or snap photos without being an artist if those paintings, sketches or photos aren’t any good.
Work for hire is one application for artistic skill. Illustrators are artists, but often their commercial work is not the best example of their artistic capabilities, even if it flexes their technical skills.
