The adapter is included for free!
I'll repeat it again.
The adapter is included for free!
What part of free do you not understand? The iPhone 7 is being sold at the same prices as the former phone, the iPhone 6, which did not have an adapter included. And... the iPhone 7 has additional capabilities, while being sold at the same price. Additionally, it comes with a set of wired headphones, not included before in the iPhone 6. The adapter and wired headphones are indeed free. If you lose the adapter, you can buy a replacement for $9 from Apple. But it is included free in the iPhone 7 box, no additional cost from the older phones.