> It comes down to whether you want type checking to work all the time, or most of the time? If your answer is "most of the time", then just use a dynamically typed language with GPT-based autocompletion. Most of the time completion and refactoring will work just fine.

This is bad advice. Such an approach will go wrong often enough to burn you, and it will go wrong silently, whereas the kind of issues you describe tend to lead to something far more visible (and therefore correctible) like a complier internal error or an IDE refusing to perform a refactor.