No, I don't keep using the word "natural monopoly" other than to tell people that the concept is bullshit.
So you are of the opinion that in (for example) industries with large fixed investments such as water distribution, electrical distribution etc. that the most efficient use of resources would be to have multiple companies competing for the same customers? That is, that there would naturally develop a situation where multiple companies would lay roads, or water/sewage lines, or electrical lines to your house, and that that would lead to a more efficient use of resources? (E.g. lower total cost for the system(s), lower cost of providing the service, and lower prices for the consumers?)
Nobody has ever demonstrated the existence of a permanent natural monopoly in anything.
Just a cursory googling for example brought up: Are Municipal Electricity Distribution Utilities Natural Monopolies?, Massimo Filippini, Annals of Public and Cooperative Economics Volume 69, Issue 2, pages 157â"174, June 1998, DOI: 10.1111/1467-8292.00077. Which points to that quite nicely. I.e. both natural monopoly and "permanent", i.e. have been so for a long time. (Of course any human endeavour isn't "permanent"). (Sorry, can't help you with full text access, you'll have to use your own library.)