This wouldn't work; Apple's entire argument is that their standards for application review are "baseline", so to speak; they're not overbearing, and are minimal

This wouldn't work; Apple's entire argument is that their standards for application review are "baseline", so to speak; they're not overbearing, and are minimally necessary for a store to have high security. (We all know this isn't true, but this is their argument). So, they allow alternate storefronts. Assumedly, these storefronts are allowed to enforce different rules, right? Are the storefronts allowed to distribute porn? This literally came up in the Epic v Apple case, when Apple argued that Epic's distribution of the Itch.io game store was tantamount to Epic's implicit approval of everything Itch.io distributed, including some pretty graphic pornography. Epic argued that this wasn't the case, and they only approved of Itch.io's governance process, not all of the content. In other words, Apple has already argued in court that there's a transitive nature to approved policies of stores-within-stores. I agree with Apple on this one! A situation with Apple approving stores-within-stores would only lead to one of two outcomes: Either these stores have to abide by the same policies the app store enforces, so there's no buff to user/developer freedom but a big debuff to user UX, or, they're allowed to make their own policies, in which case Apple is transitively forced to distribute porn (and violent content, and third party payment processors, and video game streaming services, and everything else in the area between "legal" and "Apple refuses to distribute" today). This doesn't seem fair either, does it? To some degree, to me, it feels like forcing Disney to produce NC-17 gorey horror movies. But, the situation is not identical, because Disney is not the only producer of movies for half of the US population. The better solution is not to force this through the App Store, and instead force what Android does; distribution over the internet (of either individual applications or entire stores, both should be allowed). This is fundamentally less secure, but its also how every other general purpose computing platform works. Apple shouldn't be forced to carry and distribute any and all kinds of applications, but iOS itself should be open to run any and all kinds of applications. Let the open internet handle the distribution.