You can absolutely "go fast and break things" (i.e. write prototype-quality code) in Rust, but it requires a lot of boilerplate that will be very visible in the code, and will also make it comparatively easy to refactor the prototype into a real production-quality implementation. You can't really say this of any other languages AIUI. What often happens instead is that the prototype is put in production more or less as-is, without comprehensively fixing the breakage. Rust makes it very clear how to avoid that.