You would think so, but actually a company can't sue another for antitrust violations unless they show evidence that they were injured — and the injury has to pass a two-prong test [1] to be covered.

That being said, the government can investigate without a lawsuit. But just because the government investigates, that doesn't guarantee the government will prosecute; a lawsuit guarantees prosecution, unless it's so baseless it gets thrown out by the court (which Epic's hasn't been).

Hence why Epic took a step that would obviously result in a ban: they needed the correct type of evidence of injury in order to sue.

1: https://www.businessjustice.com/the-elements-of-antitrust-in...