Why does the U.S. have so much data but only an average mood ranking (19th)?

I came across this map showing average mood across countries (based on geolocated inputs):

https://imgur.com/H9vAppm

The U.S. ranks 19th overall, even with a large sample size.

It looks pretty mixed geographically too - not terrible, but not great either.

Does this reflect your experience where you live?