So, a couple of thoughts. You can absolutely write safe code that produces wrong results. Rust doesn't help - at all - with correctness. Even Rustaceans will agree on that point.

I agree that Rust is safer than C; my point is that if correctness and safeness is the deciding criteria, then why not use Haskell? Or Ada? Both are more "safe" even than Rust, and if you're concerned about correctness, Haskell is a "provable" language, and there are even tools for performing correctness analysis on Haskell code.

But those languages are not allowed in the kernel, and - indeed - they're not particularly popular; certainly not in comparison to C, Go, or Rust. There are other factors than just safety and correctness; otherwise, something like OCaml would probably be a dominant language right now.