That system only works so long as you are prepared to be completely self-reliant, which is fine for a largely agrarian society. But at some point, technological complexity requires continued reliance on outside groups or you don't progress or even maintain.
Consider a scenario - the US falls into some weird anarcho-libertarian dystopia. This works fine for a while, but no one is making new computers or new cars or new anything and the only way to get these things is to open negotiations with outside groups. But what do you offer them? The currency is worthless because it used to be backed by a central government but it isn't now. If you don't have something that is valued by the outside group, you have nothing to bargain with. And if you don't have superior force of arms, they don't have to accept it anyway. And even if you do, you absolutely cannot trust them.
Modern government is built on trust. It has value because, even if it is somewhat corrupt, or even totally corrupt, it keeps society functioning in a way that provides value to everyone, even if it is unevenly distributed. By reducing that uneven distribution, we increase the overall value to everyone both inside and outside the system. It's literally the definition of win-win.
If the government system has some value, then its currency has value, regardless. The US dollar is valued because it is backed by the word of the US government. Other countries have lesser value because, while their word might be good, they aren't as trusted or don't have the might that the US government has at its command.
Trump and Musk and the people they're working with don't get that. They only see win-lose. They don't understand that their value is in trust and that they are rapidly pissing away that trust.
We are unimaginably fucked.
Maybe I'm preaching to the choir, and badly at that, and I apologize for that. I'm sitting down here, so far from being able to do anything effective, and it's so unbelievably frustrating.