Most of these countries are developing countries with low education levels so obviously it can't be broad, but of course in any country there will be a segment of the population who are well educated and/or affluent. Take China, most Chinese are dirt poor but because there are so many Chinese you can go to modern enclaves like Shanghai and never experience this poverty.

In general however return on investment tends to be high in developing countries because they lack so much. There are lots of businesses you can start with minimum competition. E.g. I've seen many stories about poorely educated Chinese getting rich in Africa. They start shops, facories and all sorts of stuff lacking