I think that what philanthropist can do to help is to effectively replace the government: build infrastructure, educate people, provide healthcare, employ the locals for these jobs.
Any money you give to anyone for free will just get someone rich while the rest will continue suffering.
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Also, to directly answer your point, you can give those $50 to a person OR spend those $50 to get 50 people to donate instead. This is the point of this “expensive” documentaries.