Presumably this is because the government pumped money into the stock market, and rich people hold more stocks. If the government just let the stock market crash, would people be more upset than the current situation where the rich got richer?
That's pretty different from buying up $700MM in government bonds and mortgage-backed securities, because that's something the government generally does anyway, and doing so merely provides liquidity for institutions who serve as intermediaries of these debts.
Most low wage workers earned more on unemployment during COVID.