[Silhouette]

You are arguing that the platform and the app marketplace are inseparable, but many other platforms for personal computing have not had such a store yet have been popular with both users and developers. They provided tools and documentation for developers, often for free, too. Plenty more have had multiple marketplace-like sources for new software, not necessarily provided by the same organisation that built the platform itself. From Windows to Linux distros and from Steam to the plug-in marketplaces for many large applications, there is no shortage of counter-examples to your position here.

[simondotau]

No, I am only arguing they are inseparable with respect to questions of antitrust. Obviously there's no technical impediment to iOS becoming a complete free-for-all where you can download and run any binary with root privileges using an innocuous shell script command piped from wget.

The question of what's been done elsewhere isn't relevant, because there are many elsewheres, each with their own origin stories. Most of them look more like iOS than macOS—the personal computer marketplace is something of an outlier when it comes to software distribution.

[Silhouette]

OK, but we still don't seem to have a solid argument for why Apple should be allowed, for competition law purposes, to treat different aspects of its business such as making physical devices, offering a marketplace for users of those devices to obtain software from third parties, and providing payment processing services, as inseparable. As we've been discussing and seem to agree, there is no technical reason those distinct activities couldn't be performed independently, and there are numerous examples of similar arrangements on other platforms where they are. Isn't this situation the epitome of what antitrust rules are supposed to prevent?