Harry does and Voldemort's army grows

I feel as if J.K. Rowling would have created this extravagant wizarding world just for Voldemort to kill Harry and the world to become darkness, that would have been one of the best, most controversial endings to a story in the history of film/novels. Killing off Ron or Hermoine would have blown away so many as well, however I do understand the "perfect ending" for a perfect story. What are your opinions???