[vintermann]

Sure. I said we can decide to treat things we can tell apart as non-fungible. I didn't say we had to.

If it's things we can't tell apart (say, liters of oil in the same tank), we are pretty much forced to treat them fungibly. I say pretty much, because there are such things as LIFO and FIFO accounting conventions - sometimes we do our damndest to tell apart things that can't really be told apart.

But if we can tell them apart, it's up to us. We have decided to treat money (incl. physical bills) as fungible in most contexts. With laws.

Even with laws there are limits: If someone wants to pay a debt to me, and offer to settle with a 200 NOK bill, it would be illegal for me to refuse, even if I knew this bill had been stolen from me earlier that night.

But if it was a $10 bill, or a bitcoin, it would be perfectly legal for me to refuse. With crypto tokens in general, there's to my knowledge no government on earth stopping me from declaring that I will take payment in bitcoin minted only on Thursdays.