Clojure is still massively helpful to learn, even if it is not the primary language of use. It is guaranteed to make a better programmer from anyone who has never done Lisp or FP before. It is my go-to tool for prototyping - whenever I am not allowed to use Clojure, I still first write an initial prototype in it and then translate it to the target language. Even though that sounds counter-intuitive - I am far much faster compared to if I had to write directly in the target language.
I don't really get this. If you're working in the usual OOP environment (JS, Ruby, Python, Java) what use is it modelling your solution in a functional language based on immutable data structures? Isn't that like running around naked before putting on your straight-jacket ready for work?
First of all: every modern version of languages you mentioned has some basic FP primitives; second: most of the time, it's all about the logic (algorithm) and data transformations. Yes, sometimes, it feels weird, like trying to glue every single hair back onto your chin after you shaved your beard off. And of course, the approach has certain limitations - you can't use macros, you have to be careful with recursion and lazy evaluations, etc. And it only works for small problems, and I'm not talking about maintaining big projects that way.
