Dictatorships tend to be worse than free market capitalistic societies
Corporations are accountable to their customers, after all, and don't usually have the option of literally shoving large groups of people against the wall and shooting them in the head to dump into a mass grave. Sometimes, but usually only with the approval of the government.
It comes down to who you're more afraid of, which comes down to who you trust less, and who you think is more reliant on external approval. Big Government? Or Big Business? Either one can be dangerous, but if you play them off each other, they balance out. It's when they work together that shit gets real bad real fast, to be honest.
After all, the sheperd can do more with meat then he can with wool, and a sheepdog is useful to have around.
Do you think Comcast is accountable to their customers? Our government already isn't preventing local monopolies, what do you think would happen in an even more libertarian society?
In general, when Comcast has a local monopoly, it is because it was given such by a government.
Wrong. Absolutely, positively wrong. Cable companies get their monopolies either by sitting down and carving up the country between them or by buying up all their competitors. That is the entire reason that you only see ads for cable vs. satellite and almost never see two cable companies duking it out - because the cable companies have agreed not to compete.
The fixed cost of starting an ISP and laying cable is not particularly high. The biggest barrier to entry is that municipalities and states generally won't let new competitors lay their lines or attach new ones to the utility poles, and that's a barrier imposed by government regulation, not the free market. Just look at Romanian internet: it was created more or less by kids making their own ISPs for neighbourhoods and extending them with their own wire. No cartels, no regulation, no subsidies and some of the fastest internet in the world despite Romania being a dirt poor country.
If the "cartel model" of telecom was even close to accurate, then any old idiot could make a boatload of money by starting up an ISP and waiting for Comcast to buy them out.
Can't they just share a single main line or something? Of course though, there would be bandwidth issues.
Sounds like market forces and infrastructure forced the regional monopolies and breaking them up wouldn't actually solve the local monopolies.
Bandwidth issues, and the fact that they have no real reason to share unless they're forced to. After all, Comcast (for an example, picking an ISP just because; it could be another ISP depending on where you are) paid to install all these lines; why should they let Charter (for another similarly arbitrary example) come in and use their lines and take their customers, even for a rental cost? In several countries in Europe, apparently legislation exists that would force them to lease pipe bandwidth to their competitors. In the US, the market was deregulated back in 2002 to hope that the companies would compete with each other to create new networks and drop prices. Obviously, this has not materialized; as you say, breaking them up without coming up with some system to replace them wouldn't really solve the issue in itself, and it would probably actually worsen services in rural areas.
This is how things are done in Canada, and we somehow have even worse service than the US does.
Regions basically have a government granted monopoly on cable ownership who are in turn required to let competitors use their lines. The idea was that the competitors would keep the owners honest and lead to improved service. The reality is that the line owners just don't bother upgrading their infrastructure unless they're forced to (because no one can lay new lines to compete with them), the ISPs using the lines can't improve their speed beyond the limits of the line owners, and if a customer of one of the smaller ISPs has issues with their physical connection (eg. the box is flooded or something) then they'll take their sweet time responding because they have literally zero motivation to help another company's customers.