Pivot tables are one of the most easiest and the most powerful tool on excel. If you have a lot of data and want a sufficient way of organizing it pivot tables are the way to go. Pivot tables gives you the option to break down data by categories or even sub categories.
This is an example of a pivot table that categories its data with different demographics. In this chart specifically, they compare prices and profit of grocery items in each state.
Pivot tables are one of the many ways in organizing data. And, I believe that it is a vital organizational method used in specific data collection.