> Memory safety isn't what makes Rust compile slowly, “zero-cost abstractions” is.

What one of Rust's designers told me when I asked him why they made the language so complicated is that nearly all of Rust's features exist to serve the borrow checker (except maybe macros). Once you have those features, and because Rust is a low-level language, you must have "zero-cost abstractions."

I don't know whether some other hypothetical low-language language could exist that gives you both sound compile-time memory safety guarantees as well as be a simple language that compiles quickly -- I would love to evaluate such a language, but we don't have one right now.