I think I remember hearing Holden Karnofsky give a different version of the quote in the second footnote. Something like: It's like there's not just one set of dropped keys, but there are keys everywhere. Some are in the dark, some are under the light. And you don't know where your keys are, but you have no chance of finding them in the dark, so you might as well look at the ones in the light where you have a chance of finding them. (Meaning: look at charities/interventions you have data on, because while there are probably better ones out there without data supporting them, you'll never be able to identify which ones they are.)