The nice thing about gradual typing is if you get to a proof-of-concept, you can then layer in types for static analyzers to make it more robust. Sure it's not Rust-level safety, but it works for very demanding projects. Heck, all of Instagram is built on Python, and they use the static type analysis in their workflow just like this.
It's just a compromise everyone needs to find on their own or for a specific project.
You're kind of missing my point. I'm specifically not talking about gradual typing. I'm calling your claims about development cost into question.
I'm personally not a huge fan of gradual typing. I've tried it, and it didn't work well for both technical and social reasons. But I'm not here to argue that point.
The nice thing about gradual typing is if you get to a proof-of-concept, you can then layer in types for static analyzers to make it more robust. Sure it's not Rust-level safety, but it works for very demanding projects. Heck, all of Instagram is built on Python, and they use the static type analysis in their workflow just like this.
It's just a compromise everyone needs to find on their own or for a specific project.