People with money don't put it all under a mattress. It's active in the economy, creating jobs.
Assuming you're American I believe you still have people in gov that got rich because of their family starting a pyramid scheme. I wouldn't call that a benefit to society.
Remember those guys in the 90's tanking company stocks and reputations then buying em up under the guise of saving them only to dismantle em and make their profit on the sale of the scraps? yeah they made money removing jobs.
The list goes on and on.