N.B. I did not refer to a demand newly created.
If people become richer, their demand will increase and diversify.
If you get rid of the assumption of self-sufficiency, there is a market/demand outside of the village.
However the demand does not increase infinitely without a condition.
If the productivity is improved and the supply exceeds the demand in the economic zone concerned,
then there will be no work to do as the supply becomes too much (no matter what kind of economic system you may have).