You're describing what a well designed tax system should be doing. Philanthropy is just the rich convincing us that things are fine, and we shouldn't worry that billionaires exist.
A tax system takes the amount required to fund society to the equality level desired.
In anything less than a fully-equalizing society, philanthropy still has a place.
(Said as someone who thinks higher wealth brackets, including my own, should be taxed more heavily)
I guess the Nordic societies have to really equal then, because I can't remember ever even hearing of anyone donating anything to a single school. Like.. there's nothing in the system for a school to even be prepared to even own a donation. A school over there doesn't manage a financial fund, it runs on an annual municipal budget. It's all tax money.
The parent commenter put it well, philanthropy is just the rich convincing [America] that things are fine.
Brin didn't go to every high school: he went to the one he did.
And maybe he had a terrible experience and thought it contributed nothing to his success... but that's kind of a dick perspective at a certain level of wealth, especially if a school has needs (and they always do).