The Federal Reserve, not the US government, is using up to 1.5 trillion to purchase assets, some of which are stocks. The mandate of the Fed is to control inflation and unemployment, and historically it has done so by purchasing or selling government bonds or changing the interest rate it charges to banks.

Expanding its toolset to include buying or selling non government assets is already a huge departure from historical practice.

Also, giving away 1.5 trillion and using 1.5 trillion to buy assets has a very different cost. When you give away 1.5 trillion - that costs 1.5 trillion. You will never see that money again, except in higher national debt or inflation. When you use buy 1.5 trillion in assets, you can reasonably assume you will be able to sell that for a comparable amount in the future.

I’m not saying we shouldn’t be sending money to people, but it is simply not comparable to say that 1.5T in asset purchases is an equivalent action to giving that same amount of money away.