Cable companies don't compete because the market has reached a Nash equilibrium. This is Game Theory 101. If one company lowers their prices or increase their services then as soon as others start seeing attrition they simply lower their prices in response until attrition stops. At the end of the day no one gains any customers and they've all lowered their prices. No one wins.
Similar things happen with turf wars. If I install services in one community then the incumbent can simply lower prices to match mine very easily. At the end of the day I've spent a bunch of money and may not gain any of my competitors customers. Even if my competitor is still paying off infrastructure in that region and may now be running at a lose the companies are so large one community isn't going to make a difference.
Even if you offer faster services the majority of people don't care, they just want to be able to watch Netflix as cheap as possible.