To add a git to abat's comment, sometimes "white" volunteers will be willing to go places where local people don't want to go, like remote or dire poor villages

To add a git to abat's comment, sometimes "white" volunteers will be willing to go places where local people don't want to go, like remote or dire poor villages. The most hard working people will have found their way out, and they will focus on maintaining or improving their situation rather than going back to help (except if they are really successful). At some point these places will lack educated and forward thinking people, and volunteers coming out of nowhere can actually have a positive impact, at least on the mental side. Highly inefficient globaly, but not always meaningless.