Humans are by nature generalists. We thrive in a wide variety of environmental conditions and make use of a wide variety of niches and resources. As long as we live in small groups and pursue opportunistic strategies for survival, we need to be generalists: everyone in the group must be able to handle multiple tasks.
Once we aggregate into much larger groups, some individuals have the luxury of becoming specialists. However, with the advent of social media and advanced technology, not to mention the realities of market chaos, this evolutionary aspect of business life is reversing: many of these specialist positions are falling by the wayside, and increasingly even specialists are heading towards multi-specialization. (Joe’s Shoe Repair and Fresh Croissants!)