Thomas Sowell has written a fascinating article about how “middleman minorities“ do this all over the world. These kinds of niches have been filled by Chinese in southeast Asia, Gujaratis in Africa, Armenians in Turkey, and many other places. In each case, the middleman minority gets stereotyped as a greedy blood sucker, because he is the one who must mediate between the rich and the poor people they exploit or abandon.
I disagree with Thomas Sowell about a lot of things, but this article is compellingly argued, and well researched.