One farmer works full time to grow enough food to feed everyone.
One carpenter works full time to maintain housing for everyone.
The other 18 people work full time reciting incantations to the gods to prevent their destruction.
The farmer and the carpenter are too busy growing food and maintaining housing to recite incantations all day.
So each of the 18 incantation reciters spends an extra two hours every week to recite incantations for the farmer and the carpenter to prevent their destruction too.
Then a magic stone is discovered that can recite the incantations by itself, the gods are appeased, and nobody has to work full time reciting incantations any more.
How can the islanders possibly survive now that 90% of them don't have full-time jobs?
The farmer and the carpenter are no worse off, but they think it's unfair that they must continue working full-time while 90% of the residents don't work at all.
Perhaps the farmer and the carpenter should destroy the magic stone so that everyone will have full-time jobs again.
Or is there some other way the islanders can survive after 90% of the work has been eliminated?