As for hoarding money you are misunderstanding how things work. Money hoarded are usually reinvested somewhere else and does not sleep in a vault or something. Even your bank is constantly investing the money you save on the market. Thats how you can finance companies and startups in the end.
Welfare policies have been shown at multiple times to actually harm the poor in the long run, not benefit them. There are entire books written on that topic. Check out Losing Ground: American Social Policy, 1950-1980 from Charles Murray.
There are also entire books written about Bigfoot and the flat Earth theory.
Gates and Zuckerberg have both given large amounts intending to benefit the poor.
There have been tests done which show an inverse correlation between the cost of a person's car and how likely they are to stop for pedestrians waiting at marked crossings. Just as an informal example.
It is also extremely telling that the people who litter the most are young and rich.
Rich people overwhelmingly care a lot less about people they consider to be beneath them.