Not at all, but they don't solve this problem. They help, but just because a database is in a container doesn't mean you don't need to know how it operates. Containerised databases don't necessarily come with maintenance processes automated, or may automate them in a way that isn't suitable for your needs.

Postgres vacuuming comes to mind as an example. Pre-built docker images of it often just ignore the problem and leave it up to the defaults, but the defaults rarely work in production and need some thought. Similarly, you can tune Postgres for the type of storage it's running on, but a pre-built container is unlikely to come with that tuning process automated, or with the right tuning parameters for your underlying storage. Maybe you build these things yourself, but now you need to understand Postgres, and that's the key problem.

Containers do mostly solve running the 5 built-in services, at least at small scale, but may still need tuning to make sure each pod has the right balance of resources, has the right number of replicas, etc.