In a capitalist society the consumer determines the value of any good or service. Companies must now compete to get more customers by either making a better product, or finding a way to sell their product for cheaper than competitors. In a socialist state, there is one company, and if their product is sub par, then that is what consumers are stuck with.
Capitalism allows for each individual to make more decisions about their life and business, as well as in one's ability to vote within politics. You are more in control of your own decisions rather than others being in control. Thus, capitalism offers more decision making apparatuses than its socialist counterpart.