Henry Ford had the best insight into charity: real charity is work you do yourself or money you give directly to people affected or by doing work that makes the whole world better. Fake charity is giving it to orgs that never want to actually solve the underlying issue or everyone loses their job.

A main point of that site is that different charities have orders of magnitude different impacts

GiveWell uses GiveDirectly's cash transfers as a benchmark and aims for at least an order of magnitude better impact:

https://www.givewell.org/how-we-work/our-criteria/cost-effec...

and there's still trillions of USD worth of real global health work to do:

https://www.givingwhatwecan.org/pledge

These results already account for different cost of living using Purchasing Power Parity (PPP)