My main problem with Haskell is that it never fully embraced dependent types. Instead, it kept adding one type system extension after another, making the language unnecessarily complicated.

I used to be a big Haskell fan, until I discovered languages like Lean, Agda, and Idris 2 and realized how much cleaner and more coherent the whole thing could be with dependent types built in from the start.

I highly recommend Haskell fans explore Lean/Agda/Idris. They make Haskell feel like a pile of spaghetti by comparison.