Art is not just about beauty, it is about expressing the mind (feelings, experience etc) of the author. AI will never do that (except if it learns to express its own experiences, which would be art, but not something competing with human art; it would be like if we had contact with alien art).

I have written code myself that I deem beautiful and expressive. But I'm also a musician, and making music (and listening to it deeply) has given me such intense, mystic experiences, that they dwarf anything I've ever experienced writing code. It's also much harder to make good music because it requires a kind of courage and psychological constitution that is simply not required for writing code.