I run PostgreSQL+Patroni on Kubernetes where each instance is a separate StatefulSet pinned to dedicated hosts, with data on local ZFS volumes, provisioned by the OpenEBS controller.

I do this for multiple reasons, one is that I find it easier to use Kubernetes as the backend for Patroni, rather than running/securing/maintaining just another etcd cluster. But I also do it for observability, it's much nicer to be able to pull all the metrics and logs from all the components. Sure, it's possible to set that up without Kubernetes, but why if I can have the logs delivered just one way. Plus, I prefer how self-documenting the whole thing is. No one likes YAML manifests, but they are essentially running documentation that can't get out of sync.