How does copyright limit creativity? If you want to write a new story about a boy wizard going to school, no one can legally stop you. If you want to make a new Mario-inspired platformer, no one can legally stop you.
But if you want to make money and do it from riding the brand name association of Harry Potter or Mario, they can.
But if you want to make money and do it from riding the brand name association of Harry Potter or Mario, they can.