I live in the SF Bay Area, specifically in one of the first two areas to get cable Internet in the US (@home). Since @home's deployment here in the late '90s, the only infrastructure upgrades PacBell/AT&T have deployed is AT&T's project 'Pronto' FTTN initiated in 1999 to compete with cable. The Feds gave AT&T money to upgrade Internet access for schools, which resulted in the most minimal fibre deployment in my area to each of the individual schools. They were kind enough to offer fibre Internet to homes directly along the route, and at most one block perpendicular to the route. I got fucked, being two blocks as the car crawls from the route. People behind me get gigabit, while AT&T is only offering the same lame bonded-pair 100mbps DSL that's been available here since 2005.
Comcast has only built out marginally more infrastructure, relying on their fat coax pipes backed by fibre, and increasing bandwidth as technology has been able to squeeze more from the coax.
Meanwhile, I'm waiting for the small, but scrappy, Sonic.Net to soon deploy their own fibre in my neighborhood so I can give the middle finger to the existing duopoly and give my money to a company that actually understands and cares about customer service. So much for it not being cost effective for AT&T to deploy fibre here, and Comcast stroking their coax.