This is likely if the maximum cost effectiveness is highest in global health compared to other areas. If global health is just a uniquely high leverage area—which is plausible, so many people in poor countries suffer from easily preventable diseases with terrible impacts—then it’s just going to have an exceptionally high ceiling compared to areas where the suffering is less preventable or less impactful.
This is likely if the maximum cost effectiveness is highest in global health compared to other areas. If global health is just a uniquely high leverage area—which is plausible, so many people in poor countries suffer from easily preventable diseases with terrible impacts—then it’s just going to have an exceptionally high ceiling compared to areas where the suffering is less preventable or less impactful.