One of the issues that I have with your analogy is that the monopolies you mentioned (roads, internet, rail) all have substantial physical assets that are tied

One of the issues that I have with your analogy is that the monopolies you mentioned (roads, internet, rail) all have substantial physical assets that are tied to their monopoly power. For example, even without factoring in the cost of land, it can cost up to $700k per mile of rail track. These kinds of upfront costs are one of the major moats they have to keeping outside competitors from emerging. I'm not sure the digital-era monopolies discussed have this same type of barrier to entry. The internet example is a more interesting analogy to me because it seems to align more with a utility, which we're okay with having monopolies existing, albeit regulated, because of the greater efficiencies. So are social networks, online shopping, or search public goods? If so, should they be regulated because we think there is an advantage to having a monopoly in this space? If not, what are their barriers of entry that stifle competition? I don't necessarily don't think they shouldn't be broken up, but I'm trying to understand whether/how they fit into previous paradigms or if the monopoly paradigm is fundamentally different in this digital era.