If people frequently trade lambos, then for sure it is a currency.

There are giant rocks that people in Yap trade as a currency, they don't even hand over the rock, it just stays where it was previously and it is just known in the village it is theirs.

A currency is anything more than one person is willing to trade with for something else.

I would say Hive is not outside of our tiny, tiny bubble.

But it is within our bubble, and there are tens of thousands active users here, that's more than enough to consider a currency.

Let's say we had 5 people playing D&D. Among us, we decide to use bottles of Coke as a barter system within our small group. I decide to offer you one bottle for some of your oreos. The next day, Bob, the cleric decides he really likes the look of your sandwich and says he will give you a coke if you can convince your wife to make another one for him. Would you not consider a Coke a currency in this tiny microscopic community?