To play a devil’s advocate (I don’t think I’m right, it’s just the next obvious thought), the life you save produces another two, and after few steps you still can’t. Animal charities, and I feel sorry for this comparison, in areas without controlled population tend to overwhelm themselves to the point where the charity dilutes into conditions indistinguishable from natural.

You may say, well, then help fixing the root cause. That’s right, but you have to find true one and fix it, and both is hard. Much easier to calm yourself by a donation to people who you prefer to believe to understand more.