OK, Worst-case scenario: Imagine a total breakdown of all markets, in a post-civilization scenario where people go back to be medieval farming self supporters. There is no more gas, thus no farther-than-regional trade, no valid currency, no state organization, everything is broken down...
What job will still be there?
Doctors will always be needed. Well, no one will ask for a plastic surgeon, but the doc who comes to heal your broken ankle will have a job.
Midwives will always be needed. And people will always pay one for helping them during birth.
Families who have a baby coming will pay a midwife. With silver cutlery, with things they harvest in their garden or maybe with helping the midwife to build or repair her own house if the babies dad is a craftsman.
Other than that, every small town will have an undertaker, a veterinarian, a mason and a carpenter. And a priest.