Besides the famous "C is not a low-level language" blog post.. I don't even get what you are thinking. C is not even the performance queen for large programs (the de facto standard today is C++ for good reasons), let alone for tiny ultra hot loops like codecs and stuff, which are all hand-written assembly.
It's not even hard to beat C with something like Rust or C++, because you can properly do high level optimizations as the language is expressive enough for that.
Besides the famous "C is not a low-level language" blog post.. I don't even get what you are thinking. C is not even the performance queen for large programs (the de facto standard today is C++ for good reasons), let alone for tiny ultra hot loops like codecs and stuff, which are all hand-written assembly.
It's not even hard to beat C with something like Rust or C++, because you can properly do high level optimizations as the language is expressive enough for that.