Comment by nine_k

Postgres is wonderful, and has great many useful extensions. But:

* MySQL has a much easier story of master-master replication.

* Mongo has a much easier story of geographic distribution and sharding. (I know that Citus exists, and has used it.)

* No matter how you tune Postgres, columnar databases like Clickhouse are still faster for analytics / time series.

* Write-heavy applications still may benefit from something like Cassandra, or more modern solutions in this space.

(I bet Oracle has something to offer in the department of cluster performance, too, but I did not check it out for a long time.)