IMHO, people traditionally migrated to areas with arable land. Then civilization sprang up around that arable land. As more and more people moved in, rather tha

IMHO, people traditionally migrated to areas with arable land. Then civilization sprang up around that arable land. As more and more people moved in, rather than staying valuable as arable land, it became residential/commercial/industrial land. This pushes agriculture further and further from those initial ideal conditions. This seems inevitable as long as people prefer density. Bootstrap farmers attract other farmers, which creates communities, which attracts non-farmers. That progression inevitably leads to those some of the largest communities becoming not only non-farming, but anti-farming.