Indeed, there has to be per the "case or controversy" clause of the constitution. For a plaintiff to meet standing, there must be an "injury in fact".
Epic must violate Apple's terms of use in order to be injured by the application of them, in order for Epic to have standing to allege those terms are an abuse of monopoly power.
That is incorrect, the 30% that Epic was paying Apple was sufficient to establish standing, they did not need to break the contract on top of that. The judge said so herself during the trial.
Epic must violate Apple's terms of use in order to be injured by the application of them, in order for Epic to have standing to allege those terms are an abuse of monopoly power.