The thing is, of course, that being richer, beyond a certain wealth, does not, in fact, make you better off – it may well make you worse off (people will hate you because of it, your security costs go way up, etc.).
By that pattern, the more wealthy you are then the more risk, and higher risks, you can take on without impacting your quality of life, your better off-ness. A billionaire can take on more risk than a millionaire, and a millionaire can take on more risk than waged employee.
And further in that pattern, wealth over a certain amount translates into increasing risk tolerance. And leveraging that tolerance to take on risk, and it paying off, leads to more wealth. But the only thing you can use the increased wealth, since it's beyond whatever the threshold for comparative impact is, for is taking on even more risk.
I suppose we need to have an understanding of what "better off" is and how it is measured.