An important point

From Gavin Kennedy:

Take the parable of the buyer in contact with the “butcher, the brewer, and the baker”. Most readers of the paragraph containing the parable, who have not read and understood Adam Smith in his books, Moral Sentiments and Wealth Of Nations, go hopelessly adrift in concluding that there is a clash of self-interest between the buyer of his dinner and his suppliers.

When someone buys meat from a butcher, both the self-interest of the butcher and of the buyer are served. This is not a zero-sum game; it is not the case that if someone benefits from a transaction, the other party loses.