There are plenty of reputable charities even in developed countries.
Also, I'm not sure what you mean by "enough of a difference", but I think saving one person's life for a day is "enough of a differencce" by most measures.
Enough of a difference to make the 'unfortunate' people self-sufficient. When I hear about a load of hideously overpaid rich people spending a load of money on crap and government's wasting money left right and centre, I don't see why I or other's should have to give money to others.
Perhaps I'm just not a particularly caring, selfless person