"[B]y directing that industry in such a manner as its produce may be of the greatest value, he intends only his own gain, and he is in this, as in many other cases, led by an invisible hand to promote an end which was no part of his intention….By pursuing his own interest he frequently promotes that of the society more effectually than when he really intends to promote it. I have never known much good done by those who affected to trade for the public good." (Adam Smith, The Wealth of Nations, IV.2.9)
Doing right by others is difficult and time-consuming. Hence the attraction of what I call Invisible Hand Ethics, in which we mind our own business and the ethics takes care of itself.
This is modelled on Adam Smith's famous account of how the overall outcome of lots of self-interested actions in the economic sphere can be good for society as a whole. Bakers just want to make a buck, but their self-interest produces the bread that feeds the people. Their competition for sales keeps prices down. The customers in turn just want the cheapest best bread, but wind up helping the best bakers make a good living. You get the idea. Smith argued that in the economic domain this could be a far more reliable mechanism for achieving good outcomes than good intentions.