I don't think you read closely enough: they define the failure rate as describing the likelihood of complete loss of the volume, not minor data corruption.

Unless you're mirroring your data across multiple drives, there is no way ZFS can magically recreate a volume that simply ceases to exist. Think of it this way: how would ZFS help you in your own server room if a non-mirrored disk caught fire and melted? Answer: it wouldn't. You'd go to backups, like you would with any other filesystem.