Actually, the opposite is true. The modern economy is so complex that even government cannot manage it. Who can manage it, then? The answer is no-one. No single authority or group of people can handle the volume of information, the speed of its responses and the complexity of its relationships. This is not to say that the modern economy is out of control, but only to say that the self-regulating mechanisms within it can respond more rapidly and more surely than any body outside of it. A market economy is a self-regulating system. It responds to new information and signals people to change behaviour accordingly. Much as a thermostat detects temperature changes and adjusts the heat supply, so the market detects imbalances, shortages and surpluses and leads people to alter their behaviour in ways that redress them.
Some people wrongly suppose that if the economy is not centrally controlled in some way, then chaos will result. Not so. The order of the market arises spontaneously from the millions of interactions constantly taking place. It holds more information than any group of planners could hope to access, and it is faster to react to changes than any controlling authority could manage to achieve. It is also more intelligent, representing as it does the minds of the many rather than the limited brain power of a few people grouped around a table trying to direct it.
The economy directed by the actions of many allows different individuals to purse their separate goals, where the centrally directed economy is geared to achieving the aims of its planners instead. The market economy thus allows people to give effect to their own values and priorities, to be autonomous actors rather than the agents of someone else's will. It allows for a society that is more free as well as more efficient.