Also, not sure why Azure Arc still gets mentioned. I would have expected something more cloud independent.
Our approach, for now, is to use Kubernetes Postgres for dev, test, and even stage, but cloud Postgres for prod. We have one db.yaml that in production just become an endpoint so that all of the services do not even have to know if it is an internal or external Postgres.
Another interesting use of Kubernetes Postgres would be for some transient but bigger than memory store that needs to be queryable for a certain amount of time. It's probably a very niche use-case, but the deployment could be dramatically more straightforward since HA is not performance bound.