Right now, to restore a backup using Operator for PSMDB, you have to have a valid psmdb-backup resource available. Sometimes, it's desirable to have an ability to restore PBM backup from S3 when there's no such resource. For example, when provisioning a new cluster, or when restoring a backup taken in another namespace.

It's possible to work around this limitation by attaching to the backup-agent container in one of the cluster's pods, and running pbm commands manually. However, that's not straightforward, and can introduce discrepancy in credentials leading to an unhealthy cluster (which could be fixed with K8SPSMDB-247 when a "proper" way is implemented).