A good example of how bad it has become is that modern processors have a rather good understanding of the 'string' concept, and offer instructions to process them. C offers a char.
The x86 string functionality that I'm aware of was directly derived from C string functionality, and any decent library of course uses them. You don't directly map to those underlying opcodes because that would be silly, and would completely undermine any platform independence you might have.
The same for vectorization. You don't explicitly express vectorization in your code, but of course all decent C compilers can easily and robustly generate such code.
C isn't close to the hardware (beyond very high level notions like "contiguous memory"). But it's a simple enough language that it's very heavily optimizable.