The USD's prominence in world trade goes beyond what the US is doing, let alone with that US federal government is doing. And moribund governments have been demonstrated to old on for centuries. Unwinding a system where small states have worked hard to hoard US reserves for stability will take a while to happen.
In other matters, the incompetence of the US is absolutely priced in already, like budgets for public transit :/.
Also Afghanistan is a simmering 20 year old failure. The fact that the kleptocracy we propped up was completely unstable to stand on its own two feet is more reason to exit, not less. Yes, recognizing that fact rather than partaking in more fantasy land is stupid, but expected for our incompetent money-guzzling military who didn't want to leave, but couldn't face its own shame in arguing we had to leave more slowly because we had failed so miserably.