The advantage of Haskell is higher quality code with fewer bugs even when you write fewer unit tests. The advantage is the same whether humans write the code or AI writes it.

This might not be noticeable if you only write short programs: if the human can put the entire program in the head or if the AI can keep the whole thing in the context window. It matters much more when the program gets bigger.

In my experience, AI does really well with a good type system. It tries something, if it doesn't compile, looks at the message, fixes, etc etc.

The compiler itself acts as a steering function for the AI. I've also had this experience with Rust.