Since Superman is so popular it's hard to escape being called a rip-off character, if the character can fly, has super strength and wears a cape. I've even seen threads asking if a manga/anime character like Goku is a rip off of Superman. It's all debatable. Captain Marvel was definitely inspired by Superman, but what really separates him from Supes is he is a regular person, but can turn into a superhero. Captain Marvel is the ultimate wish fulfillment.