By theory and - especially these days - by practice, private business is there to enrich its owners.
One way it does that is to serve customers, another is to manipulate, cheat, and squeeze them of every dime the business can get, and then drop them for higher-margin customers. Just look at modern business.
The value captured by the owners is a tiny slice of the value provided to the society. For example, the value I get from my iPhone is much much greater than the money I pay for it - it's just logical, I simply wouldn't buy it otherwise.
And the value received by the owners is the well deserved reward for creating the business - a very hard and low chance of success endeavor - but essential to our society.
Everything in my life is created by private businesses: from the clothes on my back, the food I eat, the car I drive, the house I live in to the computer I earn my living and write this on.
I lived in a society without private businesses, under communism, and everybody was cold and starving.
Any private business's primary mission is to serve its customers - in order to even exist.