Money is a measure of social value.
Your status in the tribe is highly dependent on your utility to the tribe, and that utility is highly-dependent on how well you work with other members of the tribe to achieve common goals. If you are more effective than your neighbor at advancing community goals, then you will have a higher social value than your neighbor.
When we were just tribes of 150-200 humans, our minds were able to store all of this social value tallying. You can intimately know everyone in your tribe. You know their credits and debits to the communal good. We have imaginations though, and can abstract some of this into stories and myths and other sorts of value systems, and so, maybe you don’t know Urgk personally, but he has a lot of cows, and you know how useful those are, so you immediately assign him some qualities in your mind.
This breaks down if you also don’t know how Urgk got these cows. Did he murder their owners and take them for his own? Did he execute some brilliant trades with tanned leather than eventually became a self-perpetuating cow-wealth machine and left the whole tribe better off? Hopefully, in your abstraction machine you’ve also codified some of the qualities of one type of Urgk and qualities of the other type of Urgk. He’s wearing a cross, and he treats his children well, so, even though you still don’t know him intimately, you at least can make some assumptions, and communicate with him directly to fill in the rest.
If you wanted people to respect you in your tribe (a VERY natural and good desire to have), then you might start trying to figure out how to build a cow-wealth feedback system too. You don’t know shit about tanning, but your weird son enjoys playing with sticks and has an idea to make everyone’s domicile a little more resilient to the weather with his weird hobby. People don’t really understand it, until they see it.
Or maybe you just decide to gain wealth by doing something that is not respectable, and yeah, you’ve got the money now, but it’s negated by the negative social value you’ve incurred, so you’re never truly respected and you never get the girl, ala Gatsby.
You’re comment is close to the mark. I’d go even further than you have and just say outright, ‘money is a store of social value’.