Perhaps I'm just not a particularly caring, selfless person
Again, I'd say saving someone's life even for a temporary duration is "enough of a difference." I don't see how making a victim self-sufficient is the absolute standard that determines whether the charity was valuable.
As for rich people and the government acting a certain way, does that make it okay for you to act in the same way? You seem to imply that the rich and government are the sole deciders of morality; and that if they aren't meeting a standard, then no one should. If you have a moral obligation either way would not be determined based off whether other people fulfilled their obligations.
It's okay if you're careless/selfish and you still think it's moral, but I don't think your justifications are sound.
And really, it doesn't have to be money. It can be any resource (money, time, energy, etc.) used to alleviate poverty (I've changed the question in the thread to show this).