Does the question posed in the title of this musing have a straightforward, even profound‚ answer? I would have thought so. In fact, when I am asked this question—as happens on a fairly regular basis—my reply is that the purpose of business is to provide a return to the shareholders, whether by way of a dividend or a capital gain, or both. The shareholders own the asset (the business), so it seems fair that they receive a reward for making the asset available. I've thought this for the long time, on the basis that the shareholders are the ones that put up the money in the first place. Staff, suppliers and others receive payments for services rendered and products supplied at the time they are provided.
However, if companies become selfish and get too greedy, by trying to maximise profit at the expense of almost anything else, as some do, then cries of protest can be expected from some quarters. Do cry-ers have a point? Maybe, but not if they are promoting some form of social engineering, whereby profits are distributed to others beyond the shareholder base. Businesses exist for the purpose of making money for their shareholders. They are not social clubs for a wide group of so-called stakeholders. Others disagree, I know, but the purpose of a for-profit business is to make a profit! Otherwise, the business would be a not-for-profit agency.
It would seem to me that, in the context of an open market, those companies that achieve dominant positions are very good at what they do. Yet no business is exempt from the invisible hand. The self-regulating behaviour of the market described by Smith over 200 years ago remains in control. It will have an effect, perhaps sooner rather than later if boards and shareholders get too greedy with profit maximisation.
So, back to the question. What is the real purpose of any business? To make a profit for its shareholders, and those that do this well, in an ethical manner, can and should expect to operate successfully for many years.