The 19th century is especially interesting because it's one of the few points in history where it benefited the rich to grant purchasing power to the non-rich.

The 19th century is especially interesting because it's one of the few points in history where it benefited the rich to grant purchasing power to the non-rich. In other words, the industrial revolution can't happen unless there is a broad base of consumers driving demand. So to the prediction that "the rich get richer until a big war or revolution resets things", you might be able to add, "or the rich decide that they can secure future riches by sharing present-day riches". In effect, they are investing in the growth of a strong consumer class to cement the demand for the widgets their factories produce.