> every person who's gotten a degree-equivalent level of skill/effort into skilled art has earned a living doing it

Not for the folks I know. I know plenty of authors, painters, photographers, and ex-film-students who need day jobs. It's practically a trope. These are people with degrees in the subject who have already made professional money at it, but can't make enough steady money with it.

(guessing here) If you met these people on the job, you'd know a lot more gainfully employed folks simply by definition.