Iirc with Fyre Festival the dude got convicted of wire fraud for defrauding an investor, not for selling tickets to a sham festival. The joke was, screw the small people, that's fine, screw a rich investor, that's when you go to jail...
I'm not even sure they could be criminally charged for a sham festival since the festival did actually happen. I'd imagine that the whole thing turning out to be a complete wreck would probably be something that could be handled in a civil case.
https://www.bloomberg.com/opinion/articles/2019-06-26/everyt...