> good maintenance is not a given regardless of private ownership or government ownership.

Its not about maintenance, its about pure math and efficiency.

Natural monopolies have 0 advantage in terms of price discovery, therefore there are no market forces. And you get all the disadvantages of a monopoly without any of the advantages of capitalism.

Many purely capitalist countries still advocate for natural monopolies to be goverment run (Norway oil being public, Singapore owning all the land and housing, Spain having public healthcare) and all of those examples beat countries that have privately owned natural monopolies.