50 year old NoSQL DB that is better than MongoDB

My favorite line from the article:

"If you’ve already mastered NoSQL and are looking for a competitive edge this is a vanishingly small pool of competitors."

Sure, IF I've already got experience in it.

The reality appears to be such that, if you don't already have experience in a particular technology, then companies aren't interested in you, even if you've worked with a plethora of other tech.

Better than MongoDB, how? The article says nothing about MongoDB.