Re: In two minds ...
Theoretically, even if you only had 1 customer but you exercised monopolistic control over access to them, you can be forced to lose control. Just no-one would bother to sue you because you're monopolizing access to Peter's wallet.
The monopoly Apple is exercising is on the aftermarket. Yes, Apple users can change to another device if they want to, but they're not the ones who are being unfairly affected by the monopoly and so they have no incentive to do so. It's developers who want to access those users who are, but since the customers aren't incentivised to move they're powerless to act against the monopolist. Since the App store is the only way to sell apps to people using iPhones, and there's no alternative storefront permitted, you must deal with Apple to access the aftermarket of iPhone users. Apple take advantage of that fact to charge rents to developers wishing to do that - a more literal 'Apple Tax' than the absurd markups on $999 monitor stands and $600 wheel castor sets.
Apple execs themselves have admitted that the app store is almost pure profit. The 30% figure was plucked more or less out of thin air, and while Apple (and Google, and Steam, for that matter) like to compare themselves to bricks-and-mortar retailers (which charge a much higher markup, so 30% looks great), most economists think a fairer comparison for what's actually provided are payment systems like Visa or Mastercard - which have been extremely profitable for half a century charging just 3%.
Other examples of this include the Epic games thing - Epic have their own payment system for in-app purchases, since they're running it on multiple different platforms. Apple shut them down because they insist on you using Apple's payment setup, even if you don't need to or want to, and then charge you 30% of your revenue for the privilege.
It's a monopolistic abuse of their position as the hardware vendor to force software vendors to pay them a tax to access users, and is far more egregious than anything Microsoft did in the 90s.
Biting the hand that feeds IT
