I sometimes prefer to enjoy the benefits of vertical integration, like Apple being able to codevelop hardware and software unrestricted from having to provide a public API at every layer (e.g. airpods device switching), and being able to unilaterally dictate user experience guidelines to app developers (e.g. ask app not to track).

For sure! It's an interesting point. But from an economic point of view, it's better for consumers if there are clean boundaries and every layer is commoditized.