For other readers: you might choose Erlang or Elixir for web services if you want high scalability with distributed communication for free, which is super important for example when building any real-time web service. It's what allows Phoenix to support millions of channel connections on a single server: https://phoenixframework.org/blog/the-road-to-2-million-webs...
Erlang and Elixir's concurrency model is also unique from what Go offers out of the box in that the way you build applications is via supervised processes with built-in failure recovery.