C++ surpassed C performance decades ago. While C still has some lingering cachet from its history of being “fast”, most software engineers have not worked at a time when it was actually true. C has never been that amenable to scalable optimization, due mostly to very limited abstractions and compile-time codegen.
Doesn’t it say something if Rust programmers routinely feel more comfortable making aggressive optimizations and have more time to do so? We maintain code for longer than the time taken to write the first version and not having to pay as much ongoing overhead cost is worth something.
How can it not? Experts in C taking longer to make a slower and less safe implementation than experts in Rust? It's not conclusive but it most certainly says something about the language.