The fundamental problem all these examples are linked to is the rise of centralized power in the economy, and the antidote has been known for a long time, see this 1952 book by John Galbraith: https://en.wikipedia.org/wiki/American_Capitalism > "...private decisions could and presumably would lead to the unhampered exploitation of the public, or of workers, farmers and others who are intrinsically weak as individuals…
The utility sector has a 10% profit margin. Hardly an example of a monopoly abusing its position. If utilities were nationalized the maximum possible gain is 10% and the potential loss is the unlimited capacity of the government to waste resources.
Maximum 10% gain is not true for example because a contracted utility has little pressure to improve services, create new services, invent new energy processes, open or serve new markets. They can go with the generic political will and collect their garanteed 10%. Private enterprise wins or loses potentially big specifically by not doing that.
Maximum 10% gain is also not true for example because there is little pressure to "do it right" from an economic outcome point of view (when to plan expansions, how to schedule maintenance). Skipping the extremely politically incorrect example.
Maximum 10% gain is also not true for example because the current sector rarely has the opportunity to expand dramatically to support a dramatic new industry. (In that case, the gain would come from the new industry - AND the expanding utility sector) Even the Pacific North West did it the other way around: available surplus energy caused new industry to settle there.