[Auracle]

Or because they knew their "power-users," as in people with laptops and iPad Pros, would prefer USB-C. They probably wanted to keep control over accessories on the iPhone not only for straight up financial reasons, but also to make sure "it just works."

Anyways, USB-C is obviously technically more advanced - but it doesn't really matter for phones much, does it? Most people only ever transfer data on their phones from/to the cloud.

[Moldoteck]

It does matter. Much faster charging, much faster transfer for prores 4k videos. The fact that a lot are using cloud doesn't mean few use cable for data transfer