No, you really can't do that easily and sometimes at all with "fiat". Which is why "money laundering" is a thing. Or drug cartels having the problem to stash or move hundreds of thousands of small dollar bills over North and South American borders.

A somewhat trustworthy state having control over or transparency into money transfers generally is a very good thing. If your government isn't trustworthy enough, you have bigger problems than the currency.

When it comes to truth, old != bad. The oldest profession is still around, for example, because demand will always be there.