I’m sorry, but you have an incredibly charitable view of human nature to assume private individuals (or private companies) are not susceptible to the vice of avarice.
An immoderate excess of “self-intrest” is destructive, be it public or private.
I never said that. I said that the most greedy (using your definition above) entity in existence is government and its bureaucracies with their voracious appetite for legal larceny of your money and your freedom. Unconstitutional governmental interference in the marketplace is like putting wolves in charge of the henhouse. The answer in the marketplace to fallen man's greed is not the worse choice of gov't, but the open competition of free enterprise.
The Left has sold you a bill of lies that legitimate and healthy self -interest is the same as overblown "greed" that lies at the feet of financially successful business and businessmen. Although greed is often present, self interest and greed are simply not the same thing.
What makes the world go 'round is legitimate God-given self interest. What keeps you reaching for rat poison for dinner? Self interest. What causes you to work hard to support yourself and your family? Self interest. Even doing things for others is guided by the good feeling you get from doing so. Again, self interest.
Government's greed is forced upon you. In the marketplace free from gov't interference, no one's forcing you to do anything. You are free to reject the greedier players and are free to chose from whom you want to do business. And in the open competition of free enterprise, over time, the greedier players tend to lose to the players with lower prices and better quality. The consumer wins in the free market which is freedom in action.
As I said, freedom isn't perfect, but it's way ahead of whatever's in second place.