Sometimes you need to push the boundaries of your agreement to show that the agreement terms are bullshit, especially if you have literally no other option.Apple isn't just "doing whatever they want" though. They will point to the court to the TOS or whatever other document that Epic agreed to a long time ago and highlight an exact line that Epic violated. They're not just making up rules.
With this, Epic are saying to the courts "Look, Apple not only completely control their entire ecosystem and have a monopolistic share of the market, but can ruin an entire entity just for adding an alternative payment option that allows competitive pricing for the consumer. Isn't that a brazen display of antitrust market dominance?"
Nothing will make Epic's case more apparent than performative action that specifically highlights the behaviours by Apple that Epic are trying to highlight.
They're basically saying "Dad, my brother hit me!" and then annoying their brother so badly that they hit them again right in front of their dad.