An example from the set of making the world better would be Bill Gates' foundation which is helping eradicate polio [0]. If that is not a good thing I give up.
[0] https://web.archive.org/web/20080414095646/http://www.polioe...
[0] https://web.archive.org/web/20080414095646/http://www.polioe...
Of course, having the state of affairs as we currently have it, B&MGF's efforts are certainly to be saluted, but that doesn't mean we shouldn't contemplate and work towards a world where you don't need to depend on the good will of a billionaire to have a chance of people not dying of various preventable diseases; Or, indeed, even to recognize that such a state of affairs is unacceptable.
It isn't clear to me that establishing yet another donor-advised trust is making the world a better place, and it seems to me as though the foundation funded by the trust is not taking action on its own initiative, but instead just giving money to those people and organizations who are already actually expending the effort in making the world a better place.
Yes, it is a good thing, but don't go overestimating the wattage of that halo on Bill Gates's head. I give most of the credit to the people who actually uproot their lives, go to Pakistan and similar environments, and try to administer vaccines to people who deeply mistrust their motives.