Indeed.interesting question. an answer might be they are in genuine markets, competition and innovation, ability to upgrade and grow, have allowed them to prosper. other utilities are under tight regulation, no real market, barely any way to change. just deliver the service, while keeping up with 100 years of decaying infrastructure.
it's too simple to mix up the why and the how. many countries privatise their utilities, keeping the companies controled, directors on the board, retaining 50% ownership, golden shares etc. UK chose to go a different route ideologically, with mixed results.
Unfortunately in the UK we handed over public monopolies to private investors, increasingly foreign, for peanuts,
with minimal checks and balances (the UK being 'a great place to do business' as the Tories gloated at the time. Course it is, mate),
which allowed them to suck out all the profits even if it involved ransacking the business.
And then in some cases they have come cap in hand to HMG for a bail out.
Which is what has happened to rail.
And which is what will happen with water.
In the UK privatization was a political maneuver.
It started as a means of unburdening the tax payer from loss making business,
especially those with Annoying Unions, like coal mining.
Bosh! Two birds killed with one stone.
Most people were secretly (or not so secretly) pleased to see Scargill defenestrated.
Then it morphed completely.
It became an electoral wheeze to create a nation of share owners, with a new vested interest in capitalism.
Tell Sid.
Sid was presented as someone given a once-in-a-lifetime chance to make a killing, and become a capitalist.
By buying into a state assest at a knock down price.
A state monopoly, that was guaranteed to make money.
British Gas.
That had absolutely f*** All to do with saving the public from subsidising a loss making business.