For the rare case where the small speedup is otherwise worth the lower producitivty of Rust, it can still be a worse choice because the you have a disadvantage in iteration speed to rework the code for a faster problem solving strategy / algorithm.
The strong and static type system makes refactoring and iteration pace extremely predictable in Rust. And it's often quick to do as well.
With dynamic languages you can pretend you're done in an hour and then endure a lot of production bugs. That's not being more productive than Rust. That's playing pretend that a complexity doesn't exist.
On the contrary, I find the speedup due to rust to be quite large and the productivity to be quite acceptable. Refactoring for me is so much easier when I can rely on the compiler to catch so much.
