Why only consider within-country inequality (and, yes, I realize that the answer is 'because it's partly a publicity stunt, and humans are biased and parochial')? The average American is incomparable wealthy compared to the average African, and you can on average save a life for only a few $thousand to one of Givewell's top recommended charities.
The poorest countries all have something in common, which is overpopulation. It seems as if the poorest have enough offspring so that they are always on the edge of starvation. I wonder if by giving them additional money, so they can have more kids, and even cause a greater strain on the local environment, have we actually done a good thing? If there is an overpopulation of deer, we don't put big buckets of feed in t…
Charity is very much better than doing nothing.