ISPs are often given franchises by local governments. They agree to make service available to a certain % of residents, even if they are not individually profit

ISPs are often given franchises by local governments. They agree to make service available to a certain % of residents, even if they are not individually profitable, and provide decent speeds to schools etc. In exchange they get access to rights-of-way to run cables and other things that make competition difficult. It's kind of a natural monopoly anyway since keeping up all the physical plant is expensive and there's no reason for multiple companies to do it, kind of like water or power companies.