IMHO

The only problem with Haskell is that it's on a journey to dependent types and they haven't released new standard yet.

It's future will depend on how good that future standard will be.

Rust is becoming more popular than Haskell because It's in a different niche (no gc). Not because it's more productive to write Rust code.

Haskell is still much easier and faster to write than any other production language.

Try to compare merge function for merge sort in Haskell and in other languages.