I'm thrilled that you have enough vocabulary to know the word "fiat", but do you know what it means and what that implies ?
It means that the State (or Country) guarantees the money and its value. It also means that the State will track down thieves and bring them to justice.
<sarc>Except when the thieves are operating in Wall Street. Those guys can steal all they want, it's legal.</sarc>
DeFi cannot turn to the State to recover anything. DeFi has no case because nothing was hacked, some smart ass just gamed the system. He actually followed the rules and used them to his advantage. There is no judge in the civilized world that will blame that guy for anything.
One more thing about fiat currency : it has two thousand years of experience being attacked, taken at gunpoint, broken into and stolen in various ways, and the sum of its rules are designed to thwart all possible attacks.
Funny money is relearning all the lessons - the hard way.