If you need a library for something in Java, it probably exists. There's several languages on the JVM these days that give you full Java interop - Clojure being my personal choice.

I think Elixir's big selling point is getting the BEAM runtime wrapped in a more modern language with more modern tooling. Lots of the positives people list about Elixir are due to BEAM, which you can also get in Erlang.