So that's all technically correct, but the point I'm making is that as that excess money is flowing through asset markets, it's ending up on the balance sheet o

So that's all technically correct, but the point I'm making is that as that excess money is flowing through asset markets, it's ending up on the balance sheet of private-sector actors who have little need to spend it on a day-to-day basis anyway. In Keynesian terms, money is pooling at precisely those firms who have a low MPC (which is not coincidental: it pools at those firms because they have a low MPC, because pooling indicates a high MPS). Thus the government needs to inject much more money through these markets than it expects, because the Keynesian multiplier is low. In the process, it inflates the paper wealth of these firms significantly more than it actually stimulates the real economy, something we saw from 2010-2020. I think the OP is alluding to the strategy of giving money directly to consumers, and particularly poor consumers (who tend to have a high MPC). This limits the pooling effect: it still happens, but it can't happen until the money has circulated throughout the economy a few times, which increases the stimulus effect for a given amount of inequality generated. As an added benefit, the effects are more immediate, which helps the central bank understand the consequences of its actions more rapidly and not have to act 18 months or so in advance of when the stimulus trickles down to real production.