I think another big benefit of Rust for systems is that you can explicitly mark functions/traits as unsafe if they require some preconditions to work correctly

I think another big benefit of Rust for systems is that you can explicitly mark functions/traits as unsafe if they require some preconditions to work correctly or if the trait must guarantee something that can't be checked by the compiler. That's a big benefit over C++ where the best you can do is documentation since the warnings in the documentation don't appear at the call site unlike how using an unsafe API requires an unsafe block/another unsafe function.