Speaking for myself, the main reason I don't get involved in AI stuff is because I feel clueless about what the correct action might be (and how valuable it might be, in expectation). I think there is a pretty strong argument that EA involvement in AI risk has made things worse, not better, and I wouldn't want to make things even worse.
Is it possible we’re talking to past each other? “Institutional reforms” isn’t something a donor can spend money or donate to. But EA global health efforts are open to working on policy change; an example is the Lead Exposure Elimination Project.
I still feel that you haven’t really answered the question, what do you think GiveWell should recommend, which they currently aren’t?
EA didn’t invent RCTs, or even popularize them within the social sciences, but their introduction was indeed a major change in thinking. Abhijit Banerjee, Esther Duflo and Michael Kremer won the Nobel prize in economics largely for demonstrating the experimental approach to the study of development.