I've also said it, with the implication that the only remaining bugs are likely to be ones in my own logic. Like, suppose I'm writing a budget app and haven't gone to the lengths of making Debit and Credit their own types. I can still accidentally subtract a debit from a balance instead of adding to it. But unless I've gone out of my way to work around Rust's protections, e.g. with unsafe, I know that parts of my code aren't randomly mutating immutables, or opening up subtle use-after-free situations, etc. Now I can spend all my time concentrating on the program's logic instead of tracking those other thousands of gotchas.