So the problem isn't one of scale, which is already huge. It's one of distribution.
Money on its own is not the solution. You can only grow an economy when people are building useful things of all kinds, doing useful things for each other, and creating new businesses.
The big problem in the US isn't capitalism as such, it's the fact that there's a layer of old and new money privilege accreted around Wall St and Washington. It's such a resource sink it has literally locked out most of the rest of the population.
It's a networking and patronage problem. The money is just a symptom.
If you're on the right side of the social firewall you can be a complete failure and still get jobs at C-suite and board level. (See recent examples from any number of tech companies - which are the obvious symptoms of a much bigger issue.)
Prosperity only happens when an economy rewards ability much more than it rewards the benefits of in-caste relationships.
This isn't even considered an issue in most descriptions of economics, but it's a huge influence at every level of business. And with the partial exception of the startup/accelerator/incubator scene, the current situation in the US has been a tragic brake on real growth.
The best you'll get from throwing money at people is temporarily less crime, starvation, and homelessness. Those are big wins on their own, but they're a bandaid and the improvement isn't really sustainable. For a growth-oriented economy, more is needed.