Earlier quoted context omitted.
> However, all of that goes over Comcast’s network because that’s my only viable choice for Internet service. An antitrust breakup of Comcast would be one or both of: 1. splitting off different lines of business, such as the content production parts from the physical cable service part, or 2. splitting them into different companies geographically. Neither of these would do much to increase your ISP options.
> Neither of these would do much to increase your ISP options. The first one works if you do it properly. One of the lines of business just operates the physical infrastructure. It not only doesn't provide video service, it doesn't even provide internet service -- the end user is never their customer, their only customers are third party ISPs, who all get the same terms.
The physical infrastructure is what makes everything on top of it possible, and at the same time it is one of the most expensive pieces to build, upgrade, and maintain. There needs to be adequate returns on investment in the infrastructure, and that's hard to do in the unbundled model.
If you want high-quality infrastructure, you need to let the infrastructure builder capture a sufficient portion of the value created by that infrastructure. Consider trains. Trains create value for people using the train to get around, but also value for the real estate by the train station. If you only let the train company recover from the rider, you won't incentives that reflect the true value of investing in the train.
Look at Japan, where train service is exceptional. The train company gets to charge both sides. They charge fares to riders, but also are major land owners around train stations, and charge rent to the businesses who benefit from having train service near them. If you had your model in Japan, where train companies just own the tracks and get a modest fee for allowing people to use them, you would not see that kind of high-quality train service.