There's a legacy connector in every box. All your legacy headphones still work. Apple didn't want to add an additional port and they can't exactly switch to usb-c at this point. In 3 years when all other phone makers drop the headphone jack for usb-c, can we get a lightning to usb-c?

And the parent is making a wrong assumption. Apple is not pushing lightning as the new audio standard. That's just a stopgap for people who insist or have the use case for wired headphones. The audio standard they're replacing it with is Bluetooth.