I should elaborate that when I write "better than nothing", I'm someone with a background in strongly-typed programming languages (OCaml, Haskell, Rust) and even more strongly-typed programming languages (Idris, Coq, Twelf).
It's unlikely that Python type annotations will ever be able to achieve something comparable to what many of these languages had during the 90s. They're useful, but if you need strong static safety guarantees, Python is the wrong tool for the task.