Also, a major differentiator is that Haskell deals with effects primarily by using monads, whereas many modern functional languages (e.g. Koka or Flix) are being designed from the ground up to use algebraic effects instead. OCaml is also embracing effects. Haskell has some effect libraries as well, but monadic code is everywhere. IMHO, as someone who loves Haskell, algebraic effects will make FP much more approachable.