The buying of new hardware isn’t an automatic, I’ll grant you, but over time, I would suspect that people might misplace the dongle that comes with the phone. As for non-Apple hardware, if it connects via the Lightning port AND the manufacturer is not gray market (i.e.: not a Chinese knock-off of dubious quality), they will have to pay a fee to Apple. The beauty of proprietary hardware is that third party hardware generates additional income for Apple. It’s quite clever, actually.