

I think you have exactly the opposite impression of wealth than how it is in reality, then. Billionaires typically have only a tiny amount of their wealth in liquid funds (what you call “holding” money) - most of their wealth is in investments, and hence “in the economy”. So the thing you’re proposing already holds.
That seems obviously false, unless you’re proposing that all the charities in the world are scams and don’t actually do anything. I guess you could argue that as you throw money into saving lives, the low-hanging fruits get picked and the cost rises, so you can never saturate all the charities - but this is a very weak argument, since saving 99.99% of all the people in the world from hunger or poverty would be about as good as 100%. Just because there’s diminishing returns doesn’t mean it’s a doomed cause.