I made the call between Haskell and Rust for my fintech startup. I chose Rust when I realized how few Haskell programmers there were available to hire - at 20 engineers, we'd be one of the largest shops on the West Coast of the US AFAIK.
That said, we were one of the largest Rust shops outside of the FAANGs, but Rust was straightforward to teach to C/C++ folks.
We actually had the opposite experience in hiring for our Haskell team: it was substantially easier to find legitimately strong engineers for Haskell than for other teams using Python and Scala. I figure it comes down to two things:
1. A lot more people want to do Haskell than there are Haskell jobs
2. Haskell is an easy way to signal (show not tell) that our team is willing to do things differently—especially important because our team was at Target, which did not have much of a reputation as a tech employer!
We didn't try hiring Rust programmers because the existing Haskell folks were more than happy to pick it up.
So making hiring easier is one of the reasons I'd want to use Haskell, counterintuitively!
Haskell is a bit of a tricky language organizationally for mostly social/political reasons, but if I end up starting my own company in the future, Haskell + Rust is definitely the tech stack I'd lean towards.