Public entities can, theoretically, be more efficient because they operate at greater economies of scale and with lower barriers. Centrally-controlled systems become unbelievably efficient when the scale is very large. In addition, public entities enjoy the absence of the shackles of profit, which allows them to make longer-term decisions.

Now, if this is really the case in the US today is debatable. But, it was the case in the past, and is still the case in many very functional countries.