An interesting exchange, although I feel like the rebuttal somewhat misrepresents Gabriel's agrument regarding systemic change. A steelman version of his argument would factor in the quantification bias, pointing out that due to extreme uncertainty in expected value estimation for some systemic change type interventions, something like AMF would usually easily come out on top.

I read him as saying that EA community would not support e.g. the abolishionist movement were it around then, precisely because of the difficulties in EV calculations, and I agree with him on that.

(I also think that OpenPhil does very important work in that direction)