I don't imagine that I'd embrace Asceticism if I were filthy rich, but what I would want to do is minimize hassle in my life. Every yacht you buy, every mansion you own, every business you haven't sold off yet, every team of presidential run advisers... they all come with layers of staffs and layers of management, layers upon layers of little nuisances to bug your brain, things that no matter how many assistants, and assistants to assistants, you have, require your regular attention.
I'm sure I would do slightly more than sipping wine in Italy, but why I would want to embrace all of that nonsense is... incomprehensible. Billionaires is weird.