iOS 8 for example takes up 5 Gigabytes, Windows 10 x64 is 11 Gigabytes.
Put it another way, could the same results be achieved with C, or even something much higher level like Haskell or Lisp, if only compilers were better at generating code?
I've looked at a lot of disassembled code over the years, and it's extremely easy to tell whether something was generated by a compiler or hand-written by a human; the "texture" is quite different.