> peering just means that ...

This also describes transit and describes getting internet service at home. I wouldn't say my cellphone peers with my provider. My cellphone is very much subordinate to my provider, not a peer.

DT thinks it's important enough that it can extort everyone.

A good policy for ISPs is to peer as many places and networks as possible, and carry traffic between your peers and customers, and customers and customers, and transit and customers, but not between peers and peers, or peers and transit. This way one end is paying for all traffic you carry. If you are a bully, you can try to make both ends pay.

> This also describes transit and describes getting internet service at home.

Well no. Transit means that you use another AS (usually by a larger ISP) to get connectivity to a certain AS. And as for your internet service at home, unless you announce an AS, you are not peering with anyone.