Billionaires exist only because of exploitation of the environment and of other people. I would never be in that position because I would never be exploitative.
No. I don't leave any money in the bank account beyond what I need to pay the bills. This is because money is often stolen from users of bank accounts, and the bank generally refuses to make them whole.
If you invest money in other people's labor expecting a return (stock market, pension, but not crypto or a house), then you are exploitative. You just don't do it yourself, you delegated it.
You're trying to equate capitalism with exploitation, but they're not the same. There is such a thing as fair market compensation. Exploitation exists when people are made to work over 40 hours a week, or they get stifled with bad health insurance, or lack a safe work environment, or otherwise taken advantage of such as with a visa issue. Not every stock investment is exploitative.
From where I sit, having more than the equivalent to a few grams of gold in personal property is very generous.