If there's a moral case for keeping the cash, it's the leverage it could provide to do something that (at least has a chance of being) even bigger. But few are the people who have legitimate reason to believe the expected value calculation comes out positively. People who feel directionless or jump on the latest Elon thing on a whim seem especially unlikely to be among those few.
(I'm not going to provide documentation, so take this for what little it's worth, but I myself gave away the majority of the several million I received for being a sufficiently early employee at the right startup. And I do not regret it.)
I recently read "The Life You Can Save" by Peter Singer, and it really does a great job of making the case for generosity even amongst middle class 1st world individuals.
ebook/audiobook are free from their website: https://www.thelifeyoucansave.org.au/the-book/
> i invest in companies and am willing to offer help to founders i vibe with for free and for no allocation