I assume parent probably meant that the worse you can do in rust (e.g use of unsafe... etc) would just put you back at C level of memory safety.

Rust has a few small but unavoidable runtime overheads compared to the best C (maybe they can be avoided with the right unsafe usage but that removed most of the benefits of rust). They are difficult to see the affect of without micro-benchmarking in my very limited experience, but C can avoid them

I am not saying that Rust is better, but not worse. Saying unsafe Rust doesn't count because it's unsafe but C gets to count feels like an unfair comparison to me: this did start out with assuming perfection on both sides.