Maybe I don't understand the realities of networking as well as I though. But my understand was that once packets enter my ISP's network, on my home connection, the rest of the way they get routed to me with protocols other than BGP. That's quite a lot of routing being done with non-BGP protocols.
Inside the major network to your cable headend or similar: OSPF or IS-IS or something else - in the largest ISPs, a combination of iBGP to get things to right area and then OSPF, IS-IS or EIGRP in medium areas.
Inside your house: almost always static routes, no protocol for exchanging reachability info.
