>you're big enough to experience this failure fairly often IMO
Please explain how? You would either have to suffer from frequent network connectivity issues that affects only your db and not your queue, or your process must be mysteriously dying in the microseconds between those 2 operations. Either of those cases are not something I would consider things that happen "fairly often," even if you were processing trillions of messages per day.
In my experience, the vast majority of message processing failures happen at the worker level.