I worked at Target on both projects using Haskell and projects using a "standard" tech stack, and we found recruiting Haskell developers a lot easier than other

I worked at Target on both projects using Haskell and projects using a "standard" tech stack, and we found recruiting Haskell developers a lot easier than other languages. People actively want to work in Haskell! Using a less common language helps you and your role stand out from the thousands of alternatives top candidates have, showing rather than telling that you're willing to do something different and interesting. Only real caveat is that you need to be willing to either hire people remotely or in larger cities. If I were to do a startup, I'd use Haskell 50% because I know it really well and 50% because it's a straight-up secret weapon for hiring.