There's more than just the physical pipe from the distribution point to your house
ISPs could compete on lack of congestion on their backbone, privacy, latency, price, "value add" features (like email, website hosting, etc), and speed depending on the model of the wholesale network
ISPs could compete on lack of congestion on their backbone, privacy, latency, price, "value add" features (like email, website hosting, etc), and speed depending on the model of the wholesale network