> How is it not subject to market forces? That doesn't make sense.
65% of domestic App Store revenue is on iOS, and the Apple app store is the only distribution channel. What market forces affect Apple's pricing power on commissions?
> Can you provide a legal document or explicit law that states "vertical integration is illegal"?
No, because like all things, it's about how you use it. Per the FTC - Exclusive dealing and exclusive distribution arrangements may be anticompetitive, however, if they are used to raise rivals' costs, exclude (or foreclose) competition, or facilitate tacit collusion. Exclusive dealing contracts may raise rivals' costs when the contracts are made with so many retailers, and lock up so much capacity at the retail level, that competing manufacturers are unable to attain minimum efficient scale in either the production or the distribution functions.
Apple is dealing with itself - maybe that argument holds in court (certainly has a shot with the current junta). It would certainly help if Congress would update the law for the 21st century. It's close enough to the line that it can be argued, and they are clearly nervous about it.
> How about this: Apple can charge Epic the same outrageous* 12% that Epic charges game developers. Do you think that would alleviate Epic's concerns?
Be mad at someone else. I don't know or care about Epic and I don't play Fortnite. I just know that private companies should not be able levy a tax or unreasonable tolls in restraint of commerce. It's hard to justify a 30% toll on 65% of a $100B+ market without at least knowing if a third-party marketplace would offer better rates and service.