You're optimizing only one of the three important things about a charity. True, the absolute worst charities are those with massive overhead, basically scams. B

You're optimizing only one of the three important things about a charity. True, the absolute worst charities are those with massive overhead, basically scams. But just avoiding those scams doesn't mean your donation will do the most good. Also crucial are: is the charity directed at an evidence-based goal? And is the charity prepared to handle more money? These are the things GiveWell checks into.