I don't think slavery was ever the dominant form for doing agriculture, except in some weird outliers such as Sparta. Because the vast majority of people were i

I don't think slavery was ever the dominant form for doing agriculture, except in some weird outliers such as Sparta. Because the vast majority of people were involved in agriculture in pre-modern societies. If almost everyone is a slave, keeping the slaves in check must be the primary job for most free people. Otherwise the slaves will revolt and overthrow the system. And if your society is little more than an oppressive machine designed to keep the slaves in check, you can't expect much long-term success.