It's actually probably a more difficult problem at scale.

When you have a single smallish schema, you export, restore, and write automated tests that'll probably prove that backups in 10 minutes ( runtime, development time few days / weeks ). Either the transaction runs or errors, and either the test passes or not.

The problem when small is obviously knowledge, skills, and procedures.

Things like:

- What if the monitoring that alerts me that the backups are down, is also actually down. - What do you mean it's no longer "safe" to kubectl delete pvc --all? - What do you mean there's nobody around with the skills to unfuck this? - What do you mean I actually have to respond to these alerts in a timely manner?

The reality is, when the database is small, it typically doesn't cost a whole lot, so there's a lack of incentive to really tool and skill for this when you can get a reasonable managed service.

I typically have those skills, but still use a managed service for my own startup because it's not worth my time.

Once the bill is a larger than TCO of self-hosting you have another discussion.