> even the metrics that RDS gives you for free make the thing pay for itself, IMO. The thought of setting up grafana to monitor a new database makes me sweat.

CloudNative PG actually gives you really nice dashboards out-of-the-box for free. see: https://github.com/cloudnative-pg/grafana-dashboards

Sure, and I can install something to do RDS performance insights without querying PG stats, and something to schedule backups to another region, and something to aggregate the logs, and then I have N more things that can break.