Apple may yet switch to USB-C for the iPhone, but Lightning is smaller and more robust than USB C so we will see, but in the meantime, there are a few minor problems with your conspiracy theory that this was all a plot by Apple to sell dongles.
- Most people simply use the earbuds that come with the phone and Apple gave lightning equipped Earbuds with every phone
- For those who have a different set of headphones that use the legacy jack, Apple gave them a free adapter
- For those very few who need more than one adapter, Apple is selling them at close to their cost at $9.
Now, what was it you were saying about there being a secret military base on the moon?