My recommendation, if practical, is a single, potentially containerized DB server that is backed by storage that provides high availability and redundancy. This is supposing that you are using the same sort of DB (ex SQL, NoSQL, etc) and that you are targeting a smallish number of services that are on-premise.

My reasoning here is that you can treat the DB server effectively as a storage API service and run it via some orchestration service like K8S. This lets you offload your DB stability and data integrity to the FS and/or other low-level stuff that is simple to configure once and only dirty about when hardware fails. This in turn greatly reduces DB server configuration and deployment as well as treat them like livestock, not pets.

Now, if you are using a public cloud provider, my view changes slightly. Generally, I'd suggest offloading the DB to a provided service that is compatible with a FOSS alternative so that you can avoid vendor lock-in. This means that you get the HA, etc without having to worry about maintenance and configuration overhead. Just be aware of cost modeling - it's easy to run up large bills.