For pop and rap, good lyrics sell songs. Relatable. Things people want to hear about. And a catchy beat, but that is secondary. The art is the words and how they are expressed.
A lot of these are more ephemeral art, they are relevant for a short period of time and go stale quickly based on shifting interests.
And that's fine. They aren't Bach, they aren't the Doors (I'm not equating the two, just very different example of "permanent art"). It's art though. I DJ school dances, almost all student suggested songs are difference every year. Except Taylor Swift.
Myself, I'm into more pure electronic music. Armin van Buren, Mike Candies, Infected Mushroom, Hardwell. Trance and psych stuff, perfect for working and driving (and thinking, so in general). The art there is the production, especially for a recorded track. Get it setup in the software, and "record" (export) one time for perfect results... Songs are built (and it's fun).
I believe AI can run roughshod over electronica. It's a very natural fit. Especially trained on quality human production, which no doubt will happen.
For the record, I purchased FL Studio back when it was Fruity Loops (they really mean free lifetime updates).
I briefly looked into ML/gen AI for MIDI composition, that seems the most directly route for patterned music (and the most flexible on the output side).