[Isofarro]

Don't learn a new language for the sake of learning a new language. Learn it because it solves a particular problem better than your existing skill set.

For example Node.js is good for tiny Web Services/API endpoints using an event-based model. Elixir for writing highly concurrent systems.

Sure, both of these can be done with Java -- since it's a general purpose language, but the result with more focused languages is a more succinct solution.