But I think the bigger factor is that Lightning makes for a better wired headphone jack than USB-C. The future is wireless, but the present remains tethered. Ever since the iPhone 7, Apple has shipped a pair of Lightning EarPods in the box, along with a 3.5mm to Lightning adapter. Apple’s Lightning EarPods cost $29, just like Apple’s EarPods with a standard headphone plug. They’re cheap enough for Apple to include in the box with every iPhone, and no more expensive than previously for customers to replace.
USB-C headphones, on the other hand, seem to be a mess. Helen Havlak wrote a piece for The Verge a few months ago titled “Buying USB-C Earbuds for My Pixel 2 Was Incredibly Annoying and Expensive”: