> The conclusion in this case is very simple: 86 billion has been taken in profits, with very limited capital investment.
What is the number for the capital investment? You’re comparing a number to words. That’s a type error.
> That's a bit more complicated, but we could at least start from the premise that had the water systems been public, that 86 billion could have been spent on capital investment without a single bond being issued
Not without knowing how much capital has actually been invested to date. Because you’d be have paid out interest and principal on that over 30 years out of that 86 billion.