Just Bill Gates, Warren Buffett and Mark Zuckerberg together will give away over 3x more than all the OECD countries on that list combined (on an annual basis). Or roughly equivalent to what Japan - the world's third largest economy - will do every ~35 years total.
Gates, Buffett, Zuckerberg, Bezos = plausibly $450 billion in combined charity over time (assuming Bezos spends ~$20 billion on space). France at the government level does $9 billion per year by comparison; it'll take France 40-50 years to match just those four private US citizens.
No other nation in world history has seen its richest citizens routinely give the bulk of their wealth away (from Carnegie & Rockefeller, to Howard Hughes, to Gates & Buffett). The scale of private US charity is unprecedented and amounts to trillions of dollars over a century of time.
Contrast that with eg Germany, where 65% of their billionaires inherited their wealth, or Europe broadly where dynastic wealth is extremely common:
https://www.forbes.com/sites/niallmccarthy/2016/10/10/where-...
Meanwhile in the US, over a hundred billionaires sign on to the Giving Pledge:
https://en.wikipedia.org/wiki/List_of_development_aid_countr...