I think if you're already documenting function argument types, there is no point. But in my experience it's unworkable to ask people to write full documentation

I think if you're already documenting function argument types, there is no point. But in my experience it's unworkable to ask people to write full documentation for every function, but requiring type hints is not as hard and is nearly as useful. It is a little weird that they look like code, but I think you get used to it.