"state sponsored" only in the sense that the state hasn't stepped in to break them up. Comcast's monopoly is entirely self-created through mergers and non-competition agreements.

No, state sponsored - or more likely city sponsored. If you attempt to run wires around your neighborhood to provide TC, Telephone, and internet (you need to do all 3 to have a chance at making money) you will be shut down because Comcast already as an agreement with the city to not allow anyone else to do it.

I'm assuming a serious plan to run wires above. That is you have found deep packet backers to fund you; you have found qualified people to do the work; you have figured out all the other details to do this. There are good reasons to stop someone running cat-6 wires everywhere, but here I'm assuming you have figured out the right way to do this - whatever it is.

And what, you think it's a complete coincidence that every single city in broad swaths of the country decided to contract with a single company to run those wires?

No, agreements between the companies ensure that only one option is available to each region. My city can offer Time Warner the right to run cable here whenever they want, but Time Warner will refuse to do so, because Time Warner has a deal with Comcast that says they will never offer cable in my city. There is no legal barrier to new cable startups like Google Fiber, only the immense cost of it and the threat of retaliatory blacklisting and throttling from the cable monopolies.

That's why the only places these companies compete are ones where the cities have decided to set up a local public broadband to buck the monopoly, or a very well resourced competitor like Google has decided to enter the market and refuses to play their anticompetition game.

Google setup their fiber in the early days based on if they could easily get permission, not where it made the most business sense (they did have some choices, but many cities didn't give them any option).

Also, in many locations, the incumbent telcos lobby specifically to block any sort of municipal/public broadband infrastructure from being permitted when it is proposed.

You can blame The High Priests of The Invisible Hand for keeping the members of the duopolies astonishingly poorly regulated, to go back to the original point of the grandparent post.

As an aside, it's funny, I'm not sure what qualifies for me as "the telephone company" anymore. I guess there probably is one where I live, technically, but it doesn't seem to factor in.

edit: this is evidently going to be one of those posts that fluctuates in "points" over time, bouncing up and down. It'd be fun to have a sparkline implementation that illustrates this change over time