Crypto is not a threat to the dollar.
Stablecoins reinforce dollar supremacy. Stablecoins can end up being one of the largest buyers of US Treasuries.
I think there is a very big chance that crypto is actually one of the things that locks in dollar supremacy.
Digital assets are one of the most important phenomena in the world right now, yet they have been ignored by national governments for far too long - Treasury Secretary Scott Bessent

“We think of $BTC primarily as en emerging global monetary alternative. It is a scarce, global, decentralised, non-sovereign asset which has no country specific risk, has no traditional counterparty risk. Based on the properties that I just described you would think of it as a risk-off asset” - BlackRock’s Head of Digital Assets