A high trust society doesn't cause a monopoly to become efficient. A society where everyone is thinking of the common good is the one where individualism works, because then you have no need for a giant bureaucracy trying to coerce everyone into doing the right thing, since they would do that of their own accord.

But the disadvantage of bureaucratic authoritarianism is even larger in a low-trust society where everyone is in it for themselves, because then you can't trust the bureaucrats not to be corrupt and they're still sitting on a monopoly.

Which is to say, what you always want is a high trust society and what you never want is a monopolist.