I am a freelancer. A client of mine wanted a solution that would allow them to scale yet not abandon the familiar PostgreSQL front-end (and rewrite a part of their source code).

Scalability aside, CockroachDB is a fine way forward from PostgreSQL and is not changing the client source code part of the system. If you are lucky and you do not use newer features from recent versions of PostgreSQL or PostgreSQL extensions, it's fine.

There are nice-to-have features for big organizations like regional tables. At the moment, my client simply does not use these. However, the serverless offer from CockroachDB is reacting well as data grows.

CockroachDB is a best practice for my organization.

High management of the CockroachDB (like creating or managing a data center across regions) seems so simple, and users can focus on developing the app.

CockroachDB is very handy.