Elixir and OTP are really nice, but I'm frustrated by the type system, even with typespecs. I finally gave in and started learning Haskell. I would still choose Elixir/Phoenix for some web apps though.
Apologies to others for the “me too” reply, but I wanted to let you know you aren’t alone, I also feel this way. It’s intellectual masturbation (without any reward/benefit), IMHO.
Haskell is a pretty decent general purpose programming language, and if used well you can produce nice programs, but the problem is that the library you need will use some clever type system stuff and suddenly you are spending hours trying to understand how it all works.
For example I'd be happy doing a lot of stuff in the IO monad with some pure bits to the side where needed. Avoid the free monads, monad transformers, type classes and all that jazz. So use it like an imperative language for the most part.
I've had the same experience with Yesod and Scotty too, although not recently - every time I decide it's been long enough for the ecosystem to mature a bit more, I bounce off issues like this which I just don't get elsewhere, and decide to give it another couple of years.
That's what one of the things that's kind of making me give up on OCaml as well although there things aren't that bad.