Rust is the most defect-free language I have ever used.

I'd wager my production Rust code has 100x fewer errors than comparable Javascript, Python, or even Java code.

The way Result<T,E>, Option<T>, match, if let, `?`, and the rest of the error handling and type system operate, it's very difficult to write incorrect code.

The language's design objective was to make it hard to write bugs. I'd say it succeeded with flying colors.

Now try an actual functional programming language. I like Rust too but those features all come from FP, and FP languages have even more features like that that Rust doesn't yet or can't have.