the Erlang vm is called BEAM, not OTP. sadly, Gleam's implementation of OTP is not at the same level as Elixir's or Erlang.
Here we are, having a technical discussion and here you are, shoving politics into it.
That aside, it is normal in Elixir to use Erlang OTP directly. Neither Elixir nor Gleam provides an entirely alternative API for OTP. It is a strength that BEAM languages call each other, not a weakness.