A lot of that is by design. It's my understanding that they made the decision not to wrap erlang standard libraries just for the sake of wrapping them, because the erlang standard libaries work just fine when called from elixir.

If something needed to be wrapped to make it play more nicely with elixir, for example to change argument order to better suit elixir's |> operator, or if there were other real benefits to wrapping an erlang library, then they might wrap it. Otherwise if the erlang library is good just use the erlang library.