I think you're confusing 'monopoly' with 'market' - which is fair enough, because everyone else does too. Essential services are rarely a mature market without state aid - which is possibly a good thing, because if you leave freebooting capitalism to run things it invariably bubbles and implodes. q.v. the number of railway companies which went bust after the UK's booms.

In fact markets only exist as a rhetorical concept, not an economic one. And you typically find idiot economists trying to scale up barter-with-cash and pretending that people making, buying and selling pins are somehow relevant to international politics and finance.

The reality is that 'markets' are an executive feature of a certain kind of political system which uses financial tyranny, debt, and strict rationing of information and political power to control and intimidate its population.

So the idea that markets can somehow be 'regulated' for periods on the order of decades is laughably naive, because the tyrants own the state and 'the markets' will change the rules of both and/or manipulate them as they choose to.

Or if they temporarily fail to have control, they'll work hard to make sure they recover it within a generation or two.

If you're lucky you'll get some token oversight. But you're not going to get much more than that without an outright ban on excessive concentrations of power and money without accompanying oversight and penalties for misbehaviour - not to be confused with the idea that if you set some boundaries around markets you can leave them alone and they'll mostly be a good thing for everyone.