This is a user to userr forum. As users of Apple products like yourself, we did not ban Fortnite.
Apple removed Fortnite from the App store, because they violated Apple's app store guidelines and broke the rules.
Complain to Epic, Fortnite's developer about it. They should not have breached contract with Apple by doing things they were not supposed to be doing without considering the effect it would have on their customers.
Apple is only enforcing the rules everybody on the app store needs to play by. Why should Fortnite be any different? Are they special? Do they just get to break the rules without any consequences?
When Fortnite can again follow the App Store rules they agreed to when submitting their game to the store, I'm sure Apple will be more than happy to let them back in.