[babypuncher]

I think it is because they had already built out a lightning ecosystem years before USB-C came and mostly solved the same problem lightning did.

This left Apple in a weird spot. They could keep the iPhone on Lightning and users could continue using the same cables and peripherals they have been since 2012. Or, they could switch. This would require many users to buy new accessories, but they could be generics that work with any phone.

The switch from Lightning to USB-C is not as advantageous as the switch from the old 30-pin connector to Lightning was. To users already invested in the Apple/Lightning ecosystem, a switch to USB-C would not bring much benefit.