Getting people to buy something doesn't always mean you provided them value. Some methods of making a buck are exploitative, like if they rely on deception, for example. There are scenarios where "middlemen" exist to take part of the wealth and not create any. Or where people are paid to be destructive for various reasons. A corrupt politician paid (in campaign donations, whatever) to pass a law to create a barrier to a market is being destructive, not constructive. It is a net loss overall.