I'm using both Scala/Akka and Elixir in production. Once you get to better know the paradigm, you'll never ever want anyrhing else. And if by niche you understand resilient backends, yes, it's pretty niche then :)
Any insights that you’d want to share with someone not using Java/Scala or Erlang/Elixir? I’d love to get the benefits of actors in Node, Python or Go, but I’m not entirely sure what I’m missing yet.
Not very sure, but actors kinda make sense in multi-threaded environments, so you can forget about Node and Python. In Go, you can replace easily actors with goroutines and channels.