I’m not incredibly privy to billionaires but to me they seem to come in 2 varieties, greedy and indifferent. Some of them think their wealth is proof that they were meant to leave their mark on the world, so they try to get even more money to leave an even bigger mark. Others might not have a personal reason to have more money, but if they’ve a banker or whatever in charge of their assets the easiest answer to any question is “pick what’s most profitable”. Even the (not really) neutral position of just maintaining wealth means lobbying against taxation. Anyone who would tell their banker not to lobby against taxation would not be a billionaire in the first place