Another reason why it’s likely more common is that it keeps things consistent.

When pattern matching outside a function head, the variable is always on the right of the = match operator since the other way around is for variable assignment

defmodule Test do
  defstruct name: nil

  def fun(x) do
    %Test{name: name} = x
    IO.inspect(name)
  end
end

You are right, they are functionally equivalent.

I tend to use the left hand side because when I’m scanning code, its the pattern match I want to focus on first. The binding is the second consideration - especially when there are multiple function heads matching on different constructs.

Just to be different I prefer in Erlang to use the left hand side. To me it looks more like a pattern match which is what I am doing.