> It is a not a problem where 'unique' or 'customised' are competitive advantages. 'Boring', 'available', 'reliable' and 'well understood' are competitive advantages.
This analysis overlooks the importance of "hype" and "convenience" in the marketplace -- case in point, MongoDB. To this day people are realizing what a mistake it was to abandon constraints and transactions given to them by their "textbook relational databases".
> Relational databases are a great way to store small quantities of arbitrary data and PostgreSQL is a textbook relational database.
Just want to make sure no one is mislead by this, Postgres scales to the amount of data needed by I'd argue 90%+ of the companies -- I'd bet my money on a single appropriately configured small-to-midsize Postgres instance being enough to handle your business needs for the next 10 years (if your company lasts that long) and beyond.
Also, Postgres's flexibility is indeed a huge competitive advantage. It can handle both full text search[0] (which I argue is usually good enough) and timeseries[1] data (better than InfluxDB can, in some cases[2]), made possible by it's extensibility. This is a competitive advantage for small to midsize companies that don't want to dedicate one person to mastery of Elasticsearch (which is often necessary), along with deploying & managing more infrastructure.
[0]: https://www.postgresql.org/docs/current/textsearch.html
[1]: https://timescale.com
[2]: https://blog.timescale.com/blog/timescaledb-vs-influxdb-for-...