We are successful because we are excellent cooperators, but why is that an advantage? We use cooperation to mitigate the biggest risks inherent in making decisions in new situations – new situations are the most dangerous times for any species.
Humans cooperate to make the most accurate determination of a situation by pooling perspectives, and to derive the greatest possible range of options by leveraging specialisation within a group. Furthermore, by pooling perspectives of the quality of the options, we arrive most often at the best decision. These are our evolutionary inheritance, and can be used as principles on which to organise our societies.
The principles are: group solidarity, and individual specialisation. Because the unique contribution of any individual is not predeterminable, group solidarity must be unconditional and universal. Because individual contribution is subject to motivation, rewards must be available.
It follows then that society must implement unconditional, universal social safety services that engender solidarity, and the only way to do that affordably is to provide in-kind basic safety services: shelter, sustenance, care, transport and access to education and information.
It also follows that a reward economy must exist to motivate individual contributions. Economy is a reasonable way to facilitate this.
Social safety as services. Rewards as money. Both are needed. Each is a distinct realm.
Money is not and cannot be social safety. Social safety is not and will not be reward.