Certain parts of the economy were booming - but doing less productive things.  Excessively low interest rates partially explain that.  A good recession means everyone suffers somewhat while those less productive operations go through downsizing or bankruptcy.  To eliminate bad management.  Or eliminate that unproductive (unnecessary) business from the market.

Fed admits money was (unfortunately) too loose.  Economics must now fix problems (and some mistakes) that were created four plus years ago.  Such as a massive tax cut for the rich.

Depth of a resulting recession will tell us how much we screwed up four years ago.  Since what we did back then has just begun to appear on today's spread sheets.