According to AI, the biggest EA charity is GiveWell, which spends about 600 million per year. 95% of the money on low-cost high-impact global health programs like mosquito Nets and vitamins for children.
There is also open philanthropy, which gives about 500 million per year to Global Health, Existential Risks, and then Animal Welfare in that order.
That said, I'm not really trying to argue the case. If the simple reason is that people have characterized EA based on SBF, and that's how they think about these things, then that is a complete answer.