True, that makes running these databases a bit easier since there are multiple nodes that can be restarted in any order. However the main point still stands: You could just as well run Postgres on Nomad/k8s by pinning it to a specific node and excluding that node from the general job scheduling pool. We do that for a single-node Redis instance for example. Still vastly superior to managing unique snowflakes nodes just for the DBs via ansible/systemd.