That's not a billion dollars company though.
Mongo equally so (JSON in PostgreSQL). These valuations are fantasy.
False dichotomy though. You either acknowledge that getting a vendor to do that for you also implies competent staff or you acknowledge that hiring "competent staff" is not like flipping a switch and requires training, ramp-up time, few wrong hires, getting managers to guide the teams, etc
I'm not sure which way is better, but I don't think the industry has decided either :)
https://techcrunch.com/2018/10/15/docker-has-raised-92-milli...