IMO the saying is more about how when you eliminate the struggle to acquire wealth, there’s less meaning in your day to day life. I’m sure folks like Musk and Bezos for example are looking for something that makes them feel purposeful, like going into space. Not necessarily trying to enrich the lives of others.
I agree though that not having to worry about bills or putting food on the table is it’s own kind of happiness. I think there’s a healthy balance.