Bill Gates pledged the same and yet his wealth hasn't reduced. Worse, the philanthropy has been targetted ideologically (like encouraging private schools) and somehow keeps ending up favouring companies he has ownership in.
In the meantime he's given away billions, but obviously he's invested the billions he still has, so unless his (doubtlessly world-class) money managers were completely incompetent he's going to at least break even.
The Bill and Melinda Gates foundation "now spends more on global health every year than the World Health Organization — not to mention more than most countries on the planet."[1]
But that philanthropy has its critics. One criticism is that it's very opaque and it's impossible to measure how effective it is. It's also both hugely influential and unaccountable.
Also, from the above-linked article:
"One 2008 article by two Oxford researchers, published in The Lancet, argued that the Gates Foundation was "misfinancing global health" — paying most of its grants out to rich countries and prioritizing infectious diseases (such as HIV/AIDS and malaria) over major chronic killers such as obesity, cancer, and diabetes."
"Another 2009 paper in The Lancet, by a group of University College London health and development researchers, found that despite the Gates Foundation's emphasis on improving the lives of the poor, its grants didn't actually reflect the burden of disease that the poorest face."
"An example: the Gates Foundation has received lots of positive press for its role in financing the eradication of polio. And yet, even that campaign had its critics, says McGoey. In her research, she found key stakeholders in some of the countries that were the focus of the campaign expressing the view that "this was really a priority of wealthy nations and not necessarily developing ones, many of which were more preoccupied with battling illnesses that created a far greater health burden in their nations [such as diarrhoeal diseases in India]. They were compelled to emphasize polio [eradication] against their will."
"Another concern that comes up in the academic literature is that the Gates Foundation is too focused on drugs, vaccines, and other technological solutions for global health problems. But many researchers, by contrast, would prefer a focus on the less exciting but crucial work of strengthening the health systems of poorer countries."
"For similar reasons, the Gates Foundation's work on malaria drew criticism from some corners. In a 2013 article in Global Society, Youde pointed out that the head of WHO’s malaria research, Arata Kochi, sent a memo complaining that the foundation "was stifling debate on the best ways to treat and combat malaria, prioritising only those methods that relied on new technology or developing new drugs.""
"The Gates Foundation has played an extremely negative role in efforts to develop replacements for strong patent rights and high drug prices," James Love, the director of Knowledge Ecology International and a critic of the foundation, writes on his blog. Or as McGoey put it: "There’s immense concern surrounding the Gates Foundation’s position on intellectual property rights, and whether this major global health player is cognizant enough to ensure property rights are fair for citizens in wealthy and poor nations."
[1] - https://www.vox.com/2015/6/10/8760199/gates-foundation-criti...