> There are some industries that are natural monopolies, like water and electricity, because it's incredibly expensive to build both last mile connections and core infrastructure.

Is this not beginning to change though? Setting up a local solar farm for a neighborhood and selling on that electricity seems like a valid business model to me. Same with setting up automated water desalinization and treatment plants. But because of regulations, the cost to do either is extreme.

I think the very regulations that add so much cost may be the one's that have us thinking all about 'natural monopolies' today. The more people you can service, the easier it is is to spread the cost of regulation. But why do you need that cost in the first place?