You should probably read the Postgres documentation [1] before you make erroneous claims like this. Postgres JSON fields can be destructured, queried, and aggregated sufficiently to cover at least the 90% cases in MongoDB usage.

I'll grant that Postgres probably isn't as much fun as Mongo, what with all its tiresome insistence on consistency and reliability. I would, however, argue that quantity of available fun isn't really a figure of merit here.

[1] https://www.postgresql.org/docs/10/functions-json.html