Not sure about this: everyone else screwed seems kind of a far reach. If you consider screwed “unable to buy luxuries” then maybe, but I consider screwed “unable to buy food” and Macro farms stand to make food substantially cheaper.

How will the four people get richer if the food they create is priced so high that no one can buy it?

I get this is deeply economic and philosophical, but it’s an interesting thought experiment.

If they can make food cheaper, what pressure is there to sell their product at a lower price? The economic answer is that a competitor will do it first to get a larger marketshare, but the pratical answer is nothing will force them. If the regulatory and capital cost to enter the market are high, then a competitor isn't likely to appear and the existing players can continue functioning in a quasi-cartel.

Taking this to its logical end, the owners of said farms will get richer as the general population earns less on average (due to their labour no longer being needed).

Before it gets that far, they build a hierarchy of underlings that oppress the labor force. (See CGP Grey's "the rules for rulers" on YouTube.)

Either that or everyone else gets fed up and violently overthrows them. It could, perhaps, be avoided with higher taxes on the rich, but the rich have the most influence over the tax code.

The government steps in and subsidizes food for those who can't afford it, either by printing money, or using taxes. The end result is robbery from the commons while your four mates who give you kickbacks and a cushy post government gig get richer.

In that case, this statement would become false:

>We really need farm workers

We really need them if we want to farm in sustainable and moral ways, as we have done by thousands of years.

But point maken

> We really need them if we want to farm in sustainable and moral ways

How so? Sustainable farming has nothing to do with a man vs machine doing the labor. Moral as in we need to make sure people can keep doing this job or what kind of argument are you even making? I'd rather see improved social safety nets and job training then some appeal to history that people need to work the fields because we've always done that.

> How so?

Modern industrial farming practices, designed to optimize agricultural output per unit of labor, are an ecological and environmental travesty. They require the widespread use of pesticides and toxic fertilizers that are decimating the biosphere. Monocropping unsustainably degrades soil quality. And the large contiguous areas used for industrial agricultural operations are extremely disruptive to wildlife.

The most obvious solution to the above is an agricultural system with many more, much smaller farms, where human beings do the work currently done by machines and chemicals.