Apple is hoping that Epic will flinch first. If this goes to court, it's possible that Apple could lose and have it's hold of the app store be broken. At issue isn't just the cut Apple takes, but the lack of alternatives on iOS devices. Maybe all of that would be fine, but Apple also produces software of its own that competes with other applications in its ecosystem. These applications have an unfair competitive advantage vs third party developers who must pay a 30% cut. Apple's paid applications don't have that additional cost and developers cannot choose a different store. Developers who want to reach that market must agree to not only the terms of the owner of the store but a competitor. Apple doesn't make games that compete with Epic, but Apple's apps are certainly going to be part of their argument.
Apple has billions to lose here so they are doing everything they can to get Epic to cave. Apple will do everything it can to delay a trial to keep the pressure on. If it does to trial, I think Epic has enough of a case for Apple to have a good chance at losing. If Apple does lose, the results are not predictable. It could mean anything from just having to allow the kind of in-app payments Epic wanted or be forced to allow alternative stores in iOS which is the disaster they most want to avoid.