Well, that would create a consumer advantage in the wealthy countries and also allow food products from poorer countries to become more competitive (assuming we didn’t just slap higher tariffs and tighter quotas on food imports).
On the other hand, this would put the poorer countries in the position of exporting more food (maybe a good thing, maybe not) and it would make the wealthy countries more dependent on food imports - which is strategically unacceptable (cf oil).