On Philanthropy

I don't understand this American billionaires suddenly growing a heart and becoming philanthropists after a certain age/ wealth level. 

Either this is not true, or our proverb - बोया पेड़ बबूल का, तो आम कहाँ से होय ? 

So, these people, who backstabbed those who believed in them, suddenly want to help millions get vaccinated? or in some other way, benefited? 

Errm.. i'll bet on the ancient proverbs, thank you. Common senses, i have found, never goes out of style.