The rich person spends the money, generating economic growth.

Except the money goes into pumping up assets like crypto currencies and other stocks. And apparently most of these assets are held by the wealthy as well. Borrow money against their shares/assets, pump up prices so that they can borrow even more money against it.

None of the money actually flows into actual investment in the real economy that would grow the economy. Look, the financials sector are thriving in COVID while the non financials are in the toilet. It is easier to get rich from capital gains appreciation than investing directly in a company for a steady cash flow i.e. expanding company size, buying new equipment for productivity. Capital gains is a risk free investment since the Fed is supporting the market. Direct investments on the other hand is risky since there are so many unknown factors that could take down a business.