Least opinionated and easiest to hack around with.
The Geospatial features are the easiest to get up and running and easiest to scale beyond single servers. On top of that NoSQL allows us to iterate features at the speed of light.
TBH, it's private. It's free. It's beautiful!
We, our team can sleep comfortable at night know "x is undefined" will not occur in production. It's also really helpful as IDE help in code completion when they know types.
Mostly using it for cache and using it as a distributed queue job broker.
Insanely fast and easy to setup with TLS certificates.