No, the opposite. Give Directly finds the very poorest people in a village (as judged by the materials their house is made from), and the Uganda study used self-selected entrepreneurs. Both of these were trying to maximize the impact of each dollar by giving the money to the people for whom it would do the most good.

Giving money to a beggar in the US would not do nearly as much good, both because the US has excellent safety nets (hospitals that will treat you, food banks) and because everything in the US costs more (so you can provide less of it to someone in need per dollar).