The sad thing is that even if you don't give a shit about other people, it would still be beneficial to make sure everyone is taken care of.
Imagine if we didn't have to worry about people stealing our bikes or breaking into our basement because everyone had enough money to not have to steal stuff.
Or if we didn't have to worry about our kids getting a good enough job because even if they follow their passion their jobs would still pay enough to have a good life.