Why do historians find periodization useful for the study of history?

Since humans tend to go through changes in periods over decades, and even centuries, it often makes little sense to give exact dates for every single instance of events. It is also a way for historians to put a general time period on an event. For example, we know that bronze became a product a long time ago, but we define its height of use during the Bronze Age. It helps generalize the 8,000 years of recorded history that historians sort through.