You haven't clearly replied to the scenario I presented and have rather used this cash analogy (and idea that if I don't address cash than the question is invalid) to continually deflect from from having to answer the original question and how it applies to cryptocurrency.
Cash is a bad analogy because it is the only widely used currency, it defines what we mean by currency, and it has always been a part of modern history in some form. Cryptocurrency has fundamental differences from a digital, public, immutable ledger.
So if you'd like to get back to the original questions, I'd be happy to continue this discussion.
However if your only defense for cryptocurrency is "cash does it too so we don't have to talk about it" then we can stop here.