If you have desperate people they will be willing to work for next to nothing. You can have them performing valuable work that adds value that customers pay for and the owner keeps the profit.

Even better is when you have different groups of people in poverty who you can use as labor pools, you can try to manipulate them or pit them against each other.. anything that keeps them destitute will benefit capitalists.

To address your question, you do need multiple classes. You wouldn't try to bankrupt the upper middle class if you have long term plans.

A feudal baron seizes on a fertile valley. But as long as the fertile valley is empty of folk our baron is not rich. His land brings him in nothing; he might as well possess a property in the moon.

What does our baron do to enrich himself? He looks out for peasants — for poor peasants!

If every peasant-farmer had a piece of land, free from rent and taxes, if he had in addition the tools and the stock necessary for farm labour, who would plough the lands of the baron? Everyone would look after his own. But there are thousands of destitute persons ruined by wars, or drought, or pestilence. They have neither horse nor plough. (Iron was costly in the Middle Ages, and a draughthorse still more so.)

All these destitute creatures are trying to better their condition. One day they see on the road at the confines of our baron’s estate a notice-board indicating by certain signs adapted to their comprehension that the labourer who is willing to settle on this estate will receive the tools and materials to build his cottage and sow his fields, and a portion of land rent free for a certain number of years. The number of years is represented by so many crosses on the sign-board, and the peasant understands the meaning of these crosses.

So the poor wretches swarm over the baron’s lands, making roads, draining marshes, building villages. In nine years he begins to tax them. Five years later he increases the rent. Then he doubles it. The peasant accepts these new conditions because he cannot find better ones elsewhere; and little by little, with the aid of laws made by the barons, the poverty of the peasant becomes the source of the landlord’s wealth. And it is not only the lord of the manor who preys upon him. A whole host of usurers swoop down upon the villages, multiplying as the wretchedness of the peasants increases. That is how things went in the Middle Ages. And to-day is it not still the same thing? If there were free lands which the peasant could cultivate if he pleased, would he pay £50 to some “shabble of a duke”[2] for condescending to sell him a scrap? Would he burden himself with a lease which absorbed a third of the produce? Would he — on the métayer system — consent to give the half of his harvest to the landowner?

But he has nothing. So he will accept any conditions, if only he can keep body and soul together, while he tills the soil and enriches the landlord.

So in the nineteenth century, just as in the Middle Ages, the poverty of the peasant is a source of wealth to the landed proprietor.

• Chapter 4, The Conquest of Bread, Pëtr Kropotkin (1892) Available at: https://theanarchistlibrary.org/library/petr-kropotkin-the-conquest-of-bread

Seems familiar...

Well ya see, if they have that dollar, then you don’t have that dollar.

So organizing the peasant revolt is a third or fourth job.