Do you barter?
By specialising, you’d swap excess production for other specialists’ goods, e.g.:
Eggs for milk.
Milk for bread.
Bread for honey.
Bartering saved you having to make everything yourself.
Naturally, if you made pins and wanted a reindeer, this could take some time and several exchanges.
And as we invented more ‘needs’ and stuff, the system became progressively untenable.