Personally I don't see him as the King of Football (I believe that Belle is also joking a bit there), but a pretty good player isn't enough. When he was at his best, he was one of the best players in the world (maybe not quite top 3, but pretty damn close).
And I'm not mentioning the Swedish championships (actually Zlatan never won that as his only full season in Sweden as a senior was in the 2nd best Swedish league), but he has won several of the best leagues of the world playing a key role in several of those teams winning).