I’d argue that Ford and Carnegie foundations are not good examples here, having veered very far from the intention/goals of the original donors into directions that are arguably diametrically opposed. Essentially they were hijacked from within by hired “professional managers” who pursued their own agendas. Maybe in the future we can set up AIs to make the decisions on our behalf after we’re gone, because humans are extremely unreliable over longer time frames!
It’s also not unheard of to structure a foundation to just run their assets down over time exactly on the theory that, given enough time, who know how the money will be distributed.
