Modern agriculture depends on the technology that is created by the other 40-70% of the population that works. Additionally you have to compensate the people in agriculture with something for their labor.
> The fact that starvation is possible in a rich country is by design. It is not a necessary fact of the economy.
It's also a consequence of human rights. We have decided that forcing people to work in the field so that other people can enjoy the benefit of their labor without due consideration is wrong.