You can easily create tables that look just like pivot tables using PQ that do the same grouping and analysis of data.
True, but that limits what you can do with result.
Unlike pivot table, you can't use slicer and other tools to slice and dice data in different manner quickly.

Pivot table allows for quick expand/collapse of grouping details, time intelligence, without change to underlying model/data.
Linking multiple tables via slicer to present same segment but with different summary etc.