Well, nothing except almost the whole ecosystem of libraries not having type annotations, those type annotations that exist themselves being quite limited (IIRC

Well, nothing except almost the whole ecosystem of libraries not having type annotations, those type annotations that exist themselves being quite limited (IIRC), etc. etc.? Can we stop pretending that adding type annotations to a 'dynamic' language solves the "good static typing" problem? It's just silly. (About as silly as pretending that static types solve all problems.)