I don’t think that’s self-evident. In practice private companies can often be a lot more efficient than the government, but there’s a more fundamental objection too: taxpayers can choose to invest the money they save from paying lower taxes into the private utility company and by doing so they get the same amount of “free money” that they would have saved by paying more taxes upfront for a government-owned utility. In other words, if owning a utility company is so great, you can do it yourself via the free market rather than via the government.
More efficient does not equate to cheaper for consumers, it just means more profits for the owners. A private company will always maximize those profits at the expense of the consumer. A public consortium has no need for profit and can spread costs evenly across all users based on usage.
Your whole point lacks any semblance of the reality of inequality, the reality of being poor or even middle class. The absolutely non sense idea that a private utility company would even sell you shares or that even if they did that owning some tiny amount of a company is the same as being part of a democratic process or that for profit companies can even be allowed to make choices that are counter to making profit.
I will accept that existing bureaucratic schemes and liberal democracies are lacking and we can do better but its not by privatization.
