According to Adam Smith, in a free market system, the market would control by itself by the factors of demand and offer. He called these factors "the invisible hand" and he thought the government didn't have to interfere with the market because it was ok by itself. However, Smith's model of capitalism didn't consider the standards of quality, nor the labor conditions for workers and the control of monopolies.
For example, if the market only followed the trends of demand and offer, the companies would try to abuse their workers in order to produce more, or they will establish monopolies (control) of good and services in order to raise the prices. Imagine little towns where there is only one internet provider, if the company didn't have any governmental controls and limitations, it could charge crazy amounts of money for the internet service, when in reality it doesn't cost as much.