Unfortunately it’s antithetical to human nature. There’s zero evidence I’ve seen that we can ever work honestly for universal, communal good at any great scale.
I encourage you to read the essay "Are we good enough?" By Peter Kropotkin. It was written in 1888, and provides a useful starting point in exploring this concept.
A few choice opening lines: "One of the commonest objections to Communism is that men are not good enough to live under a Communist state of things." and "Men are not good enough for Communism, but are they good enough for Capitalism?"
There was a man who wanted to adapt the economy to human nature. His name was Silvio Gesell. He called his economic order "natural" not because it was a constant of the universe, but rather because existing economic theories expected the humans to adapt to the economic system, they had to be convinced and forced to do things against their will in communism and capitalism.
Even if you disagree, consider this: the economic system that is being proposed can coexist next to a capitalist or communist country. The reason for that is that the hoarding of gold or non-demurrage currencies only harms the division of labor of the countries still using gold or non-demurrage currencies. People who claim that demurrage is unnatural can just go ahead and do whatever they want. It doesn't harm the system at all. There is no exploit or escape hatch which ruins it.
As weird as it sounds the exploits that people come up with only work with the conventional currencies, because they have this misconception about holding money being the same as saving money. Holding money is more akin to hitting the pause button in a video game. If people understood the economy was a multiplayer game kind of like Civ 6 with each turn being delayed until a player ends his turn, you could take a bath for half an hour while the rest of the players have to wait, then the waiting people would get angry and know exactly who they are waiting for. Unfortunately money is anonymous, so we don't know who we are waiting for.
To prove that holding a turn (hoarding) is not the same as making a decision (saving), consider the hypothetical case where you could play the next 20 turns in one go and then take a bath. Nobody should be angry about your decisions.
> And precisely, therefore, they must not continue living under the present system which permits them to oppress and exploit one another.
The whole issue is that every system permits "them" to oppress and exploit one another. Capitalism works because it embraces our instinct to do this and tries to turn it to everyones advantage. Communism has no answer for what to do about this problem. Capitalism is designed to succeed when people are selfish, and it turns out most people are. We might not be good enough for capitalism, but we sure are bad enough for it.
See, capitalism doesn't try to turn it to everyone's advantage. It turns it to the advantage of wealth. It immediately ensures a socioeconomic caste system of nobility, workers, and freeloaders. Nobility freeloads but convinces workers that those beneath them are there because they're parasites. It gives the illusion of economic democracy while ensuring the ruling class can live in luxury as they always have. People like to pretend you can regulate capitalism into something else but capital always wins and capital regulates the regulations.
Im not going to claim capitalism doesnt have problems. Clearly you are right that it leads to inequality with freeloaders. Its just that every single economic system has this same problem, and the non capitalism ones also suppress innovation and growth. You know the ruling class in every communist system has lived in luxury, right?
Experimentally speaking the nobility, workers, and freeloaders seem to be independent of the system. Even the attempts at communism ended up like that (although horribly organised).
Capitalism has a plan for how to cope with that dynamic and make sure that the powerful don't break the capital that modern society depends on. Non-capitalist systems don't seem to have a mechanism to do that.
