Music industry is a economics of superstars. https://www.jstor.org/stable/1803469 Very few stars get huge profits and after that it's long slim tail.
Talent or high work ethic is not enough for success, "getting discovered" aka someone likes you and invests the initial money and effort is another factor.
If personal effort is not enough and the artist has nothing else, selling your ass for an opportunity to earn millions is pretty damn reasonable transaction. I mean, if Jeff Besos would come to you and say: I invest into your startup $100M if I can fuck you into the ass tree times, very high percentage of HN crowd would immediately say yes.