I might be missing something, but the appeal of gradual typing to me is that I can mostly type functions, providing safe input/output boundaries, and avoid having to type every single variable (unless I have to do so for performance reasons, as I do in Common Lisp).
This approach is comfortable to me both in Erlang and in Common Lisp, I see it as a balance between safety/performances and development speed (and I'm saying that as someone using Go for all professional development and being really happy with its full static typing).
This approach is comfortable to me both in Erlang and in Common Lisp, I see it as a balance between safety/performances and development speed (and I'm saying that as someone using Go for all professional development and being really happy with its full static typing).