The working class are paid to produce goods and services which are then sold for a profit. The profit is gained by the capitalist class because they can make more money selling what we have produced than we cost to buy on the labour market. In this sense, the working class are exploited by the capitalist class.
The capitalists live off the profits they obtain from exploiting the working class whilst reinvesting some of their profits for the further accumulation of wealth
Production is started not by what consumers are prepared to pay for to satisfy their needs but by what the capitalists calculate can be sold at a profit. Those goods may satisfy human needs but those needs will not be met if people do not have sufficient money.