IMHO the biggest reason for Rust is that developers NEVER get enough time to write perfect code. All this takes time and management usually doesn't grant you that allowance.
In a perfect world where developers could tinker with the code until it's perfect we wouldn't need Rust. This is not that world.
Not even that. Because if your language isn't expressive enough, you can't make code perfect. Or rather, "perfect" in one language is than worse than "good" in another language.
Imagine big but perfect Assembly codebase against an okay-ish Rust codebase. Which one would you prefer to maintain?
In a perfect world where developers could tinker with the code until it's perfect we wouldn't need Rust. This is not that world.