Comment by samiv
In a healthy economy flow of money is like the flow of blood in the arteries. It is what stimulates the economic activity. You can't earn a dollar without someone spending that dollar. Spending = earning = economic activity.
People are always defending rich people (capital owners) that they invest their wealth. But actually if someone has a billion in the bank the fact that they have that billion is a proof that they didn't invest it. (If they did spend it or invest it the would not have it, now would they?)
A billion that circulates in the economy is much better than a billion that sits in someones bank account. Someone who spends 100% of their income is much better economic citizen than someone who doesn't.
Banks don't just keep your money in a vault when you store it in a bank account - that would be stupid both of both the bank and of you. Money looses value over time due to inflation, so banks reinvest 90% of your stored balance into loans, stocks, bonds, etc. This means that a theoretical 1B account, would allow someone else to take a 100M loan to fund a new venture. This is how banks make money, and they pay you a small portion of their profits as interest on your money (since they're profiting off it).
This is still not a good idea for you, as the interest doesn't make up for inflation. Most people keep a small portion of their wealth in the bank, as easy access for emergencies (this is called dry powder[0]). The rest is typically invested into private equity, which allows new ventures to be created.
It's very rare for anyone to have more than $50m in the bank. The money is usually out in the market doing it's work.
[0] - https://www.investopedia.com/terms/d/drypowder.asp