Only because they don't feel threatened by it. The uptick in high profile infrastructure ransomware attacks is the first penny to drop there. A second will one day be high inflation rates for the USD. I don't pretend to know when that happens, but history of fiat currency is clear that it will happen with certainty eventually.

Bitcoin cannot succeed past a certain level because then it competes with the USD and becomes a threat. One way or another its days are numbered.

Don't forget the US outlawed gold at one point. Competition with the fiat currency monopoly will not be permitted because it undermines the sovereign power wielded by the state.