Hickman isnt saying that mutants will replace humanity. In fact Hickman is saying that mutants will NEVER replace humanity that a conflict against the humanity will lead to the extermination of mutantkind always.
Chales and Magneto are depicted as proud and stupid. Hickman story even stablish that mutants are by definition less intelligent that humans, even the most intelligent mutant is not near of Stark , Richards , etc.