I think from Apple's perspective here Epic's move did two things. It denied both Apple and Epic revenue by decreasing sales. It moved revenue from Apple to Ep

I think from Apple's perspective here Epic's move did two things. It denied both Apple and Epic revenue by decreasing sales. It moved revenue from Apple to Epic by moving the commission on the sales that did happen from Apple to Epic. I believe this is what they're complaining about with the "lined Epic’s pockets at Apple’s expense", i.e. they are arguing that they are entitled to that commission on the transactions that went through the 3rd party payment provider.