Value is not necessarily the same for everyone, you can have situations where everyone profit.
People just don't want to believe in an idea that there is a solution out there, which thrives on the idea that two people can profit individually without any one of them suffering any loss. Money could be specific but value cannot be specific, 2 people can value same commodity differently because of the intensity of their wants, the more marginal value it has to them.
True, trading profit both party, as long as there is division of work and unfulfilled demand
In modern society, very often majority of the demand is fulfilled, each producer are dumping excessive goods in an attempt to get most liquid assets (usually money) from the other, then it does not benefit anyone