I think the subtly in the argument is that there are monopolies and alternative to monopolies and associated trade offs with those states.
So the question is: are there cases for which a monopoly has a better cost/benefit ratio than whatever the alternative is.
If you take a look at utilities, then theoretically, the upfront cost is passed on to consumers. So two different power utilities would spend twice the capital, which would then need to be passed on to consumers. Twice the repairs after a storm, twice the cost for infrastructure updates. The end state is what we see with home internet, you get a monopoly, but none of the monopoly regulation because "there's competition." Then there are mergers to watch out for, cartel behavior, etc.
So my assertion is that when you apply regulation to a monopoly it might be better than the alternatives that probably need regulation anyway.
> This happens in all cases.
This is mildly off topic, but I think it applies here. This is a statement of inevitability about what is fundamentally a political battle. If, for example, citizens united was fixed, the tax burden for people who have over 10 mil were large, and corruption was criminal and prosecuted as such, then I think it's harder to make this argument.
I think this idea of inevitability is the result of learned helplessness.
I think the idea that monopolies will always exist in a state of conflict with the citizenry is true, but I don't think it's a foregone conclusion that the monopolies will definitely win. I think they are winning right now, but I think the idea that that their victory is inevitable is self defeating.