It is the complexity of economic systems, and their constantly moving equilibrium positions, and the existence of decentralised knowledge which renders central planning useless. It is the same complexity which renders mathematical and statistical modelling of economic systems potentially dangerous, except to give pattern predictions. Modern economists also have a better understanding of other aspects of the role of knowledge. Much knowledge is subjective. Costs are subjective.
Preferences are subjective.
The results of our actions can rarely be foreseen. The world is non-linear. But there is a further point of greater importance. Intuition and spontaneous thought are responsible for much of progress and many good decisions. Intuition is not a substitute for rigour and hard work.