> if you have billions that could be spent on taking tangible action to change such taxation
Do you have evidence he didn’t try? He’s been a prolific (albeit measured) donor to candidates who have pushed for this [1].
From what I can tell, Buffett enjoyed making money. He outsourced his philanthropy to Bill & Melinda Gates. Their focus has tended to be global poverty.
[1] https://www.opensecrets.org/search?order=desc&q=warren+buffe...
Those numbers are a pittance relative to his wealth. He could have established a foundation and given it hundreds of millions of dollars specifically to push for a more equitable taxation system. He did not do that.