The problem with this logic, is that Apple isn't really a "business" in this case. Epic and Apple aren't really "business partners". Apple is an unregulated privately-owned quasi-government entity with none of the responsibilities or checks on authority that a real government has.
You can sue the Post Office, lose your case, and know they can't retaliate by stealing all your mail forever. You can sue the Department of Labour, lose a case, and still have the right to hire employees in the future. You can sue the Fire Department, lose a case, and still reasonably trust they won't burn down your house. You can sue your local Power Company, lose your case, and still trust that they can't unilaterally ban you from ever buying Electricity again.
But you can't ever sue Apple, over anything, ever, no matter how evil Apple is, no matter how heinous Apple's activity may be. Because no matter how valid or correct your complain is, no matter what happens, they'll just black-bag your entire digital existence in retaliation.
Apple is acting like a Government, Apple is ruling like a Government, but Apple has none of the oversight or accountability we'd demand from any reasonable Government.
Folks are thinking of Apple like it's just a video game console, when the more apt comparison is Comcast or AT&T. Apple shouldn't be allowed to control what does or does not live in the App Store, for the same reason that Comcast shouldn't even be allowed to decide what websites or services you do/don't use.