Fiat can certainly play fiat games with Bitcoin. For example the leverage that hedge funds and investment banks can use to pump or dump the price of Bitcoin can make Bitcoin seem more volatile than it is. There's also similar dynamics happening with altcoiners that use Bitcoin in their treasury like Luna or Celsius. Ultimately, though, the scarcity of Bitcoin is absolute and these fiat games that these organizations play have a finite shelf life. Hence, when the leverage is unwound, we get back to normalcy, so the damage, in other words, is temporary.