Economic literature isn't just philosophical or theoretical, it is empirical as well. The only empirically falsifiable theory here is that monopoly is natural for all businesses. The world's oldest profession, prostitution, has never been run by companies the size of Standard Oil. Neither has wheat, sugar, electricity production, coal, iron, or copper. Only revisionist history would take such a limited view of the economic scope of the world. If monopoly were the economic end state of all industries, surely some of these old industries would have been monopolized by now...or at least they would have been before Anti-Trust law was a thing. Note that that has not ever happened.

A natural monopoly only exists in the face of high barriers to entry. Those barriers may be natural, or they may be political, but either way they must be high. Some may be high enough to only have a few competitors, but compete they must do. Collusion is mathematically and empirically unstable. In fact, the economic criteria for cartel success is a) how much profits increase, and b) how long they last. There would be no need for `b` as a success criteria if they were stable.