Scala is not necessarily a detour in this discussion. It's arguably the most functional language among mainstream ones. And for better or worse its ecosystem se

Scala is not necessarily a detour in this discussion. It's arguably the most functional language among mainstream ones. And for better or worse its ecosystem seems to be influenced by old Haskell hands much more than one would expect. So what we have seen in the last ten years is probably a good proxy for using a real functional language in the industry. Akka comes to mind as another example of what you said about Finagle. It works great and even has voluminous documentation. But every time I try to click through it in Idea to see how it works I kind of don't see it. This contrast with most other libraries is very real. From speaking to other people I know that I'm not the only one who feels this way. Broadening horizons aside, I'd rather not have production issues with such a codebase. Personally I don't doubt that Haskell developers are smarter than me. Though I strongly suspect that they come from a hard to reproduce background (PL theory majors? CS postgrads? theoretical physicists?). And not that many companies require this level of sophistication. There's a huge disconnect I see in the real world. Intellectual bottom scrapers such as JS/golang are increasingly popular. Yes, we see golang catching up with Java ten years later than was necessary but it only confirms the observation. Scala and even Kotlin (F# too?) are not that widely used for how practical they are. In this world I see no place to be found without a looking glass for something as esoteric as Haskell, lazy evaluation and all. And we've had this exact conversation for a decade already.