...Superman existed

Have you ever asked yourself how the world changed if a hero like superman really existed ? Would the earth be a better place ? Would crime rates drastically drop or would nothing significantly change?

You can't necessarily tell from the appearance of superman that he is a hero. At the first glimpse, he seems like an ordinary human being. The cape might hint that he wants to look like a superhero but no one would suspect anything because he would be the first hero to exist in the real world.
However, even though he looks ordinary he has the power to be as quick as a bullet and so strong that he could stop a driving train with his bare hands. His incredible power could either amaze people and lead to  him being worshiped as a hero. Or his abnormal power leads to the population fearing him because he could turn into a potential threat that can't be beaten.
In the "superman" films, he is displayed as a good hero who uses his power and time to make the world a better place. Superman tries to solve conflict and saves people but could he also stop a war ?
Furthermore, there a so many issues, conflicts and wars all around the world. Would it even be possible for him to solve multiple problems at once? There would be so many people asking for his help. He would have to decide who to help first. Some people might feel offended that their problem might not be superman's priority and blame him for the unsolved problem. The dislike towards Superman would grow and might cause further conflicts.
Moreover, Superman might not have the time to solve all problems, or he arrives to late so that the incidents becomes irreversible.
All in all, even if Superman does not  ensure world peace he definitely will influence the crime rate in a positive way. He could serve as a further contribution to the already existing police, firemen and other real life heroes.