Good on them for finding Elixir useful, but none of the benefits they talk about seem very compelling for me. Most of them are available as table stakes in other languages (rerunning failed tests as an USP of mix test, really?), or very situational/subjective benefits. I find the import system in Elixir to be very opaque, making it hard to know where a function is coming from after it's been aliased and use:d. I subjectively find explicit import statements much clearer when debugging code.
The final drops for me are the missing explicit return statement, and the extraordinarily bad tracebacks on error. If I could I would excise Elixir from our company.