Types can help eliminate errors and unwanted behavior, yes. Just like tests.

Types also help document code. Just like tests.

The point is that both are investments and both have different payoff matrices. Sophisticated are often better at preventing obscure logical bugs. They're also good at uncovering obscure not-bugs and preventing code from getting out until the compiler is satisfied. Bad unit tests also do this.

Haskell simply takes longer to write than other languages. Given two developers of equal skill and experience, anyway. I partly attribute the relative paucity of haskell software out there to this.