Functional differentiation can be considered a division of labor on a large scale. Law, politics, economy, education, mass media, science, art, healthcare, etc., divide up the labor of society. If this division of labor works efficiently, a crisis in one subsystem won’t throw the entire society into chaos. This is the virtue of decentralization. For instance, there might be a global financial crisis and law, art, science, education, etc., can continue to function. Unlike an animal body, society doesn’t have a brain or heart that can be targeted to bring everything down. We might consider the centralization of physiological processes in the heart or brain a weakness in the evolution of animals. The individual body is at the mercy of things like bullets, brain tumors, and carbon monoxide.
Communication/society, however, carries on despite the deaths of about 151,600 people each day.