Earlier quoted context omitted.
I would think that any many decently populated areas, it's at least a "duopoly". You would have the cable company and the phone company competing. I have a choice between Comcast and AT&T.
This is a short-term situation that is already mostly dead. The pre-existing infrastructure of POTS and CATV wiring was re-purposed to provide Internet connectivity. But the last-mile POTS infrastructure is completely saturated and xDLS services cannot compete against DOCSIS. Comcast can upgrade you from 20Mbps to 1Gbps by replacing the box down the street and selling you a new modem. AT&T has to dig up the street an…
Phone companies just need to invest in putting the DSL modems closer to the households, say at the neighborhood cabinet rather than the switching station. A literal mile is too far. VDSL2 can do 100Mb/s in each direction at 500 meters, and there's no bandwidth contention with your neighbor. And VDSL2 is extremely mature, hardly the state of the art. By comparison, at the office I pay $450/month for dedicated 100Mb/s fiber service from Cogent. And the POTS infrastructure is just about as reliable--which is to say, very reliable.
I live in San Francisco, which is already extremely dense. AT&T owns the POTS system, but they refuse to put in the investment. My switching station is almost 2 miles away. I finally got fiber from Sonic.net. They're investing in hanging fiber over much of the westerner half of the city at a time when AT&T is hemming and hawing about upgrading their cabinets. And interestingly, my fiber service runs straight to that switching station 2 miles away.
The only reason cable dominates is because the phone companies aren't interested in competing. AT&T and Verizon own a huge amount of the POTS infrastructure, but are entirely focused on mobile and cable. It's a ridiculous state of affairs having so much infrastructure managed by the same oligopoly. When I cancelled Comcast and told them I was only paying $40/month for Gigabit fiber there was a long pause--he was absolutely incredulous. Was it a promo price, he asked. (No.) He knew there was no chance of retaining me as a customer.