Whether or not we accept that this is possible and whether or not we are willing to make the changes necessary is our choice. But it is not a thing that happens so much as a thing we make happen.
We could do the same thing except instead of basing the money on the collective willingness to attack the neighboring village it could be a collective willingness to feed, house, and medically care for the neighboring village. You couldn't press people into it will fear like Caesar did, but hope might work. Money a proxy for what people believe in, and beliefs can change.
I still don't understand where the money comes from, who is paying for people to grow food and farm the land? Is this only a local community idea, because I am talking at a global level. We see that "hope" doesn't work at scale, people are inherently selfish and don't necessarily want to help others beyond their current community (and even then, that can be a stretch), therefore, creating a profit motive where both parties of a trade are better off is what caused the single greatest change in human standards of living in the world. "Hope" is not what achieved that but rather harnessing human greed as its own force and steering it into productive pursuits.
Even without the Romans, look at how the US banking system works. Money enters circulation when people are granted loans--loans which are issued based on the banker's belief that the debtors' endeavors will succeed. If the technology for providing these necessities improves to the point where it is believed that they're easy to provide (some may argue that it already has), then we can create new money based on collective support for that goal.
This money could be more legitimate than what you get from a banker, because it is backed by activity which obviously benefits the people. By contrast, when you accept a dollar you have no way of knowing whether the loan that put it into circulation was for activity that helps you or harms you. Collective trust in bankers is pretty shaky, and yet it still seems solid enough to keep the current system afloat. Collective support for solving the basic-needs problem would be a much sturdier foundation for a monetary system.
The point is, "there aren't enough resources for that"-style argument only works for resources like metal or water or labor... things that we can't create from thin air. Money is created from thin air to meet the needs of the system. If there's enough collective willpower to get something done, a lack of money can't stop it because we can just change the way money is created in support of the desired activity.
- money based on which loans bankers will grant (e.g. the status quo)
- money based on ensuring that people's basic needs are met such that they're able to take on more economic risks with their free time (re: starting businesses and such)
What do you suppose the merits of the former are?
It's not about altruism, it's just about what works best. I think there's a lot of evidence to be found by just looking around that the former isn't working especially well. The only thing holding the latter back is buy-in, and if things continue to deteriorate there will have to come a point where giving it a try makes more sense than continuing to base our money on arbitrary decisions made by people we don't trust.
This is not how logic works. Saying that one system is not working well (which is, again, debatable, see how China and Japan grew in the last 75 years) is not evidence for another system working better. Ultimately you seem to have a naive view of the world and not much understanding of macroeconomics. I will have to point you to a textbook because I cannot explain it all from this level of understanding.
> Look at all of the growth we've achieved, high-five guys!
What information I have from my travels and conversations has lead me to believe that the global market has been more of an exploitative force than an uplifting one, but I'm perhaps a bit too young to have a basis for comparison. I wasn't really aware of these things at a time when I could have a "before" snapshot. I just see the cracks in the "after" one.