We are past that now. Now we have advisors, funds, elite accountants, and all kinds of dead easy ways to invest and keep huge wealth long term, for even the most inane person. Plus those people are not accountable to anyone. It's not like a hated heir of a royal who has to tread lightly anymore, lest the senate or the people take them down...
In fact, inane people can even make a great fortune from scratch in this era, what with the various famous-for-being-famous celebrities...