I think people underestimate how long fraudulent / ponzi schemes can last. Madoff's ponzi scheme ($65B) went unnoticed for ~50 years until a whistleblower got the SEC to take notice, and it could have potentially gone on a while longer if that hadn't happened. There's a lot more money in the crypto-sphere, and no great way to regulate. I wouldn't be surprised if lots of these entities are able to run on for 100+ years before they implode.