Oh they are definitely using it, but no one is going to admit it.
You misunderstand the workflow. I'm not trying to create a text prompt that generates hits. It's a way to get ideas and find interesting stuff rather than doing it manually with a guitar or on the piano. Then you have to walk away for some time to clean your sonic pallette and try again.
As a lifelong musician I am absolutely loving all the conversation around this stuff. Musicians steal everything, all the time. The idea of some genius that sits down and pops out a hit in 30 minutes that comes deep from within their soul and has all the meaning attached to it is a myth. We're trying to make things people can connect with. Yes, some musicians are doing it for the sake of art, but not most, and even with a lot of those, it's just an image they project.
When you hear a song, it has probably gone through half a dozen different versions and was worked on for months. These new AI music generation tools will churn out 100 different ideas from you to borrow from and cut the revisions down quite a bit I think.