Ponzi?

Yes, thank you. Fixed. Auto-incorrect strikes again.

I don't agree. I believe currencies not backed by countries have a real use in the world, and labeling any and all as a Ponzi scheme is a misnomer. Anything has value if we assign it, and even if 5% of the world considers crypto valuable I'd call that a successful currency, to those who value it.

Value is not the criteria for currency - otherwise Magic cards and Beanie Babies would count.

Currencies must be widely accepted in exchange for goods or services. Crypto is promising, but it's not there yet.