An exceedingly dangerous activity indeed.
The problem is that meaningfully helping others often requires self-sacrifice. Solidarity is a shift in perspective, to extend the self around others and act in the collective interest.
It’s not exactly uncommon for systems set up to oppose something to end up supporting them instead. See the ADL covering for Elon and condemning those opposed to genocide as antisemitic. In theory the ADL should be opposed to fascism, but because Israel has become fascist they found themselves on the same side as those who had been and would be their oppressors.
Of course it isn’t just sitting around unused, it’s being reinvested to make more money. Billionaires typically put most of their net worth into assets and stocks and then live off of loans, just like the comic I posted alludes to. Just because they don’t have literal piles of cash sitting around doesn’t mean they aren’t absurdly wealthy.
And let’s be honest, if a billionaire wanted a Scrooge McDuck style gold pile they could have it arranged within a week at most.