[juhatl]

One major thing would probably be OTP, which would be very difficult to implement as-is on top of Go. A recent comment thread [1] over at Lobste.rs explored this in more depth.

Saša Jurić made an absolutely wonderful hands-on presentation [2] of what (oftentimes rather unique) value propositions Erlang/Elixir/BEAM bring to the table. It's a very tightly-packed presentation, but I strongly recommend having a look if you're curious.

1. https://lobste.rs/s/ntati1/even_go_concurrency_is_still_not_...

2. https://www.youtube.com/watch?v=JvBT4XBdoUE