Hiring doesn’t really seem to be a problem for Haskell teams in my experience. Onboarding can be a little slower, but there are a lot of developers out there who want to work with Haskell. If anything, I would consider Haskell a hiring advantage.
Hiring for Haskell has never been a problem anywhere I've seen.
I've worked profesisonally in Haskell for 9 years now.
When working as a consultancy, whenever we hired for ourselves or our clients, we got 5x more applicants than we were looking for. Of those, around 80% got a hire recommendation (unfortunately we couldn't hire them all).
When hiring 1 role for our startup, we got 40 good applicants immediately, with a single post on Reddit.
In all cases we had the luxury of picking the best-fitting among many excellent engineers.
Maybe you'll face issues if you want to hire 100 people on the spot. But most companies don't have that problem.
If you want to hire five developers, Haskell makes that easier. If you want to hire five hundred developers, Haskell probably makes that harder, although it's not something I have experience with.
