Why would anyone contribute more than is required to get what they need, if they’ll never see any benefit beyond that?
I prefer a system where people that work harder get more so they can have what they want, rather than just the bare minimum to survive (which is presumably what is meant by “what they need”).
Defined by man that have never worked honest day in his life and lived off family, repeated by people that don't know human nature well enough to know it doesn't work