Neither Erlang nor OCaml bring with themselves the burdens of purely functional programming and the sophisticated type systems that you talk about. You also mentioned Scala and that one too is extremely pragmatic and lets you mix and match both OOP and functional concepts instead of sticking to purely one paradigm. Erlang is dynamically typed and OCaml does not mark side-effects with types and force you into the monadic context for all such side-effecting computations.

Purely functional programming still remains a purely academic exercise because it fetishizes type systems to the detriment of all other concerns in software engineering. Although I do enjoy some of the things that come out of that kind of work, e.g. parser combinators.