What's to stop you, using your 18+ ID from buying crates of alcohol and giving it to random < 18 year olds for the lulz?
For one, I have to do it in meatspace so it's easily traced back to me, whereas anonymous tokens can't be traced back to me by design.
The minute this scheme went into place, there would be sites based in one of the "stans" selling tokens for a couple bucks to whomever wanted to buy.
Because those <18 year olds will immediately flip and identify you to the cops to try to lighten their punishment.
The anonymous crypto token scheme does not have any trace-back mechanism like this at all. If there's no way to track those tokens back to you, why not sell them for $1 each on the internet to make some extra money?