While much has been said about smaller,  flatter organizations, an article in The Harvard Business Review observes that the managerial class in business has been growing, not shrinking, since the early 80s. In the U.S., the number of managers, supervisors and support staff in the workforce grew by 90 percent between 1984 and 2014, more than twice the growth of other occupations, at 40 percent, said the HBR. The same article also notes that more Americans are working at large organizations. Between 1993 and 2013, the number of Americans working at organizations with more than 500 employees went from 47 to 51 percent. The proportion of Americans working at organizations of 5,000 or more people also went up, going from 29.4 to 33.4 percent in the same time period.

This might explain why there are so many more managers now: organizations this large have lots of moving parts, each of which necessitates people to supervise them. The article also notes that business is much more complex, with far more attention being paid to things such as risk management, diversity, information technology and an increasingly Byzantine set of regulations on both the local and national level, which could also lead to businesses employing more managers. 

Whether or not this is a good thing largely depends on how one views management and bureaucracy in general. The sociologist Max Weber might praise this development, as he believed, that "from a purely technical point of view, a bureaucracy is capable of attaining the highest degree of efficiency, and is in this sense formally the most rational known means of exercising authority over human beings.  It is superior to any other form in precision, in stability, in the stringency of its discipline, and in its reliability." In contrast, the sociologist Antonio Gramsci took a more jaundiced view, saying that "he who by profession has become a slave of trivial details is the victim of bureaucracy." This is the view taken by the article's authors, who likened the growth of managers as a cancer. Regardless, though, it would seem that reports of the death of the large hierarchical organization have, so far, been gravely exaggerated.