Realistically, on the one hand we have the option to incentivize Apple to be an intermediary by letting them increase the price of everything by 42% and pocket

Realistically, on the one hand we have the option to incentivize Apple to be an intermediary by letting them increase the price of everything by 42% and pocket the difference. On the other hand, we have the option to ban this practice, and force big app stores to allow alternative payment systems. This will, as you state, predictably lead to some developers building their own insecure alternative payment systems, selling private information, and other negative outcomes. Sometimes it works fine, though. What we're unlikely to get is some utopia in the middle where you can select a sign-in and payment option in each app, where you can choose between paying $5 to Apple and letting them be the intermediary, paying $3.50 to the developers directly, or perhaps paying $3.61 using a 3% markup intermediary.