Most people don't realize that Excel (like PowerBI) has an in-memory, compressed, column store database inside of it.

Loading hundreds of millions of rows into it takes a while, but given a commensurate amount of RAM and a reasonable data model (single table or star schema), performing aggregations with a pivot table is pretty snappy.

PowerBI is quite nice too.

Well, for me with my personal PC with a quad core and 24gb DDR3, it gets unusable for about 1 million rows, but it's true that most of my datasets have around 10 columns or so.