Pretend the $20 million is guaranteed, and if anything will increase slightly over time.
What problems could be significantly improved for $20 million?
(I am dreaming of winning the $1.55 billion Powerball drawling. Then taking the lumpsum, posting taxes, investing, and spending 4% each and every year. I understand that the actual may be more, or less than the started amount.)
That first parts is the best way to get harassed to hell and back. You don't really want to give money to everyone, they'll come back to beg some more, and get angry/violent/dangerous when you won't anymore.
There's the magic of not giving a shit after. But good point, it's entirely possible to do this to some extent as an anonymous benefactor. And at $20mil annually guaranteed income I could always hire someone to do it for me.
Also, I'd be buying remote wilderness and building a self sustaining off grid homestead and not telling most people how to find me. I don't like visitors.