They are mostly a non-scarce fleecing operation backed by a marketing gimmick.
Now in that case, he's flashing around cash, which is not that uncommon say in certain locales (Las Vegas comes to mind). In that case, the cash you received doesn't lose any value. Though you may get questioned by the police.
Now ink stained bills and bills glued to each other should be rejected since they were likely from a bank or atm heist. But that makes it easy to spot.
Isn't that what BTC was trying to compete with?
"Diamonds are bullshit" and people only think they have value because of a De Beers marketing campaign in the early 1900s.
https://priceonomics.com/post/45768546804/diamonds-are-bulls...
Plus a ton of other discussion: