> Seems ironic that you’d use rust to “build fast”. My impression is that Rust is more about building things safe/correct and efficient, with developer productivity being lower relative to other modern languages.

I have to admit that I have limited experience working deeply with Rust, but I've found thus far that my relative productivity is inversely proportional to the size of the project. That is, for large projects, Rust is much more productive than other languages. For small ones, less productive.