That's one of the reasons why the Great Depression was so bad: the US was on the gold standard at the beginning. The US can't create gold out of thin air, so the USD started deflating, people stopped spending, and capital stopped flowing. Companies went bankrupt, people lost jobs — all because much needed dollars were stuffed in people's mattresses instead of being spent.
The Fed is increasing the money supply by purchasing bonds because corporations need cheaper capital to pay their workers and their bills. When the pandemic is over, it will sell back these bonds the banks it bought them from. Without the Fed's intervention, this recession and pandemic would have been far, far worse.
Of course, helping corporations also helps the people who own the corporations: the rich. That's a distributional issue, and the main solution is tax policy. We need to raise income and estate taxes on the rich, increase the tax on capital gains, and institute a wealth tax.
The Fed is like an engine. But engines are a tool. Tools can cause good things and bad things. Right now, the Fed is causing good things by providing liquidity, which has the side effect of causing bad things because it lets the rich accumulate wealth.
If the Fed is like an engine, then it serves to move a train — the economy. If the train is runaway — if the economy benefits the rich far more than normal people — that doesn't mean engines are bad. It means we need to stop the train, fix it, and start the engine again.
If we restructure our economy, the Fed will still continue to do good things, with fewer negative side effects. That would be, on net, good. So the problem isn't with the Fed, it's with the economy. And claiming that the Fed is the root of all our problems misses the bigger picture.