Static typing is a very bad software development practice. There are a lot of other software development practices that are superior to it.

"help you in refactoring" It's a terrible way to refactor your code.

There are far better and far superior software development practices out there, which do everything static typing does and more.

"There is no way around verifying your assumptions about types" Yes, there are. There are many many ways to do this that do a lot better job than static typing. Static typing is known to be terrible at eliminating bugs from code.

The complain here is not that static typing isn't better than nothing but that static typing is such a low tier solution, that if you were doing anything proper you wouldn't be touching it.