Because humans don't also take inspiration from other's work they've heard and unconsciously repeat part of other songs they've heard before, possibly decades ago. Never happens. Never. Humans don't profit from books they've read and apply to their career. Humans don't profit from watching other humans do the thing and then learn to do it themselves.
All AI does is do the same thing but at ridiculous scale and ridiculous speeds. We shouldn't hold progress because capitalism dictates that we shouldn't put people out of jobs. We need to prepare for the future where there is no jobs and AI replaced all of them.