Comment by IAmBroom

You are inventing a meaninglessly broad definition of currency.

Gift cards are a credit system (a proxy) for existing currency.

No one trades credit scores for goods.

The next three function are bribing a socially powerful person, because they don't work in reverse - Kim Kardashian is never going to do me a favor in exchange for mentioning her on my IG.

Trading cards are scarcity trading, not fungible proxies for wealth. I've gotten a reduction in price for an antique via a cold Coke, during a hot outdoor antique show, but that doesn't make cold pop cans currency - I wouldn't have gotten twice the discount for two of them.