Hmm... do you not have a credit card? I often reflect on how paying with dollars seems so disadvantaged in today's economy. If you plan to pay back on time, why would you ever use dollars?

I'm not sure your in group/out group thing really holds up. I think of your credit/wife examples as not "credit" but something like basic reciprocity, closer to barter.

I think it's just a bit of blurring of terms. In my mind, bullets and ammo are just not currency in the same way a coin is. You can call it a "pseudo-currency" but the pseudo is kind of cheating.

I'm also not sure "There are lots of documented examples of currency emerging spontaneously from trade between groups where the groups all mutually decided that one type of object had value" disproves the point about violence/government. Can't I do the "pseudo" move back at you? What is the mechanism of the "mutual decision"? Would it be unlike the ones that lead to states? It sounds like everyone agrees something has value so we can have a dispute resolution mechanism. The implication being if you don't agree the other choice is violence? What if I say this "spontaneous collective of groups" is a "pseudo-government"?

Where would that leave us?

We should be careful to distinguish when credit-cards are used for credit purposes versus the common scenario where they're just the default/convenient payment method and a debit-card could substitute just fine.

Kind of like how the local church might traditionally manage birth/death/land records, but that doesn't mean the documents are sacred or a religious observance.