" Farmers there have automated. As will American farmers, once they can no longer rely on illegals."
Some crops don't "automate" very well, most that do, have been.
If you have some ideas on how to do it, you should invest a few million into a farm and give it a try.
Sorry, I don't buy the arguments of the cheap foreign labor lobby. There are plenty of countries that are self-sufficient agriculturally without relying on hordes of ill-paid foreigners. Australia and Argentina come to mind, not to mention America before 1965.