I feel that Erlang adoption is probably the most realistic growth path for most serious Elixir developers. All of these topics you mentioned (breakers, message routing, etc) have been discussed and developed in the Erlang community for years. The only new thing that Elixir brings to the table in these areas is abstraction and syntax - both of which are arguably not needed in large complex systems.
Source: full-time Erlang developer of 7 years who spent a full year coding Elixir in its v1.0.x days
Source: full-time Erlang developer of 7 years who spent a full year coding Elixir in its v1.0.x days