That's because Epic maliciously violated the terms of service.

In fact they did so deliberately to help them in their court cases.

Gatekeeper/notarization are intended to stop malware, which Unreal Engine is not. Apple may well have a valid business dispute (over another application on another platform), but it's an abuse of the system and control they have to obstruct a Mac owner from running non-malware software on their own computer.

Luckily the court stopped them retaliating in this case, but it gives me reason to be concerned about expansion of the "it's Apple's device and will always act in Apple's interests over the owner's" mentality from iOS towards Mac desktops.

Maliciously is a stretch. If a rule is unjust then violating is just IMO.

It’s not a stretch at all. The court explicitly found against Epic on this point.

They had to violate it to be able to sue. That's not malicious.

That’s simply a false statement, and it’s hard for me to believe you don’t know that, since it’s easily checked.

How would they have standing to bring a suit if they had not tried to challenge the Appstore rule?

Anyone can sue over unlawful contract terms without needing to breach the contract.

The one finding in Epic’s favor was that Apple violated California’s Unfair Competition law by preventing Epic from linking to an outside payment method.

Epic could have sued over that at any time.

Not when you have signed a contract… come on this is law not Robin Hood…

Plenty of contracts include dubious and outright illegal things, depending on the jurisdiction. I'd say Apple is violating the public trust as they increasingly corner the market in apps and phones.