My vague understanding is that Fortran can actually be faster than C in certain numerical calculations because the language doesn't make the same kinds of guarantees. And therefore, Fortran will live forever.
Fortran disallows pointer aliasing and it has some language intrinsics which operate on arrays as a whole, so the compiler can emit processor-specific SIMD instructions. I'm sure that a very clever programmer could use restrict and inline assembly in C to get similar benefits, but you know as well as I do that having the language make these guarantees for you is helpful.