The issue here is that from a business perspective, developers are not the end users of iPhones. Consumers are. And I find it pretty interesting that in the numerous pages of responses here, I don't seem to have picked up any discussion of what any of this means for the end user.
For what it is worth, I do genuinely feel that the App Store does offer consumers legitimate benefits in the form of better privacy, security and ease of use, flawed as it may be. However, the problem then comes when these benefits, while good for us, may not be so great for developers. For example, the ability to track my subscriptions within the App Store means that it is actually easier for consumers to terminate subscriptions, just as iTunes means that developers never actually get our payment information.
While there may be some genuine reasons for wanting to move away from the App Store or at least be able to use alternative payments, I find that more often than not, what's good for developers may not necessarily be good for consumers. That's why larger companies like Epic, Spotify and Facebook are beating the drum so hard about wanting alternative app stores and third party payment options. It's less about benefiting the consumer, and more about wresting more control for themselves, and being able to steer users to their own app stores.
I am pretty sure any potential future Facebook App Store will not incorporate ATT, for one. Will it even support Apple Pay?
And maybe as a consumer, I don't want any of this. Maybe I bought an iPhone knowing very well that it's locked down with just one App Store and maybe to me, that's a feature, not a bug.
Maybe the App Store doesn't exist for developers. It exists for us.