That’s rather uncharitable; the fallout would at least be similar to what would happen to the holders of SGD, NZD, DKK, and dozens of other currencies smaller than Bitcoin were they to implode.

[1]: https://fiatmarketcap.com/

There's no such thing as market cap of a currency - just circulating supply denominated in itself. Each of those economies would be devastated and left unable to conduct commerce. Bitcoin though? A handful of speculators.