As many others said in the thread, forget about the relationship between Ruby and Elixir, and give Elixir a try. It is much more than syntax: structs, protocols, the test framework, documentation, tooling... even the new error messages and debugger make a big difference on every day development.

There are reasons for picking Erlang over Elixir but if the reason is that "Elixir does not offer anything beyond syntax", it is likely the person has not been paying much attention.