By that logic, the burger flipper at McDonald's should be able to pocket all the money McDonald's brings in.
Don't ignore the fact that the employee's contribution is only a small component to the success of the business. Just because someone comes up with cool superhero drawings doesn't mean he alone also brings those to market, negotiates comic book, movie, TV, and other licensing deals, creates the content and publishes that content, or any of the hundreds of other jobs that go into the production including managing payroll, paying bills, etc.