My claim wasn't that it didn't fulfill their needs, it was that it doesn't fulfill all needs (gamedev is one example that I'm familiar with).
Postgres storing JSON types != All mongo functionality
I'm sure I could achieve everything I'm doing in mongo by some roundabout way in Postgres, but if you're doing a large amount of reading/modifying partial fields within JSON structure, it's the exact use case for mongo.
1) it's a proof of concept that others have improved upon to show that you can indeed replace the functionality of mongo that most developers tend to rely on.
2) neither has mongodb at that level
3) that's correct, you need to actually use the term SELECT when you use the functions
and you are correct, pg is missing the random data loss that comes with mongo. it will never be 1-1 in regards to that.
EDITING TO ADD:
the important part is the note (the bulk of the comment) that I'm updating partial JSONB data on a very regular basis, and do it using PLV8, getting rid of the need for an unreliable database and instead using exactly what this news story is about.
Postgres storing JSON types != All mongo functionality
I'm sure I could achieve everything I'm doing in mongo by some roundabout way in Postgres, but if you're doing a large amount of reading/modifying partial fields within JSON structure, it's the exact use case for mongo.