It’s not worthless. The United States, which happens to be the largest economy in the world, requires taxes to be paid in dollars, regardless of how you’ve settled your transaction. If you and I trade a car for 40,000 chocolate bars, the IRS demands we figure out the dollar cost and pay them their due.

If I owned all the dollars, the US would simply decide to start demanding taxes in something else because it could not use those dollars for anything. If it refused to switch to another currency, it would not be able to pay the people who would force me to pay taxes, so there would be no reason for me to pay taxes.

The United States can print more dollars. Hell, they can declare all your dollars not real and throw you in jail. Every dollar is owned by the US Government. You’re just borrowing them.

The US Debt is denominated in dollars. The USA has promised to pay its entire $24+ Trillion debt, in dollars.

But that would not make any sense if one person held all the dollars. The creditors would have no use for dollars, and the US would need to switch to another currency in order to be able to pay its employees. They could print however many dollars they wanted, and could pay back the debt that way, but that would not solve the problem of the dollar no longer being useful as a currency. The government's employees would have no reason to accept the dollar because nobody else would accept it. The dollar is primarily valuable because it's used as a currency. If it stopped being used as a currency, its value would be zero. This is no different from Bitcoin.

If you had all the dollars and people still had to pay their taxes in dollars. You would be able to get a LOT of stuff for those dollars because everyone would need them.

The actual concern with this argument is that "You can only pay your taxes in US dollars" is a backing that is contingent on the policy of the US Government. The strength of that backing depends on your view about the likelihood that such a policy will stay in place. (Edit: granted, if all USD were owned by a single entity, the likelihood that such a policy would be revoked is much, much higher.)

It does depend on the policy, yes, but note that government backed (local) monopolies exist in other areas too. Like for example with hospitals, or with phone network operators.

I'm not sure how this comment relates to the topic as we aren't discussing any sort of monopoly.

If you have all the dollars then you have a monopoly on them. If the government forces people to pay their taxes in dollars you have a government supported monopoly. It stands and falls with the government's support for it, the connected regulations, etc.

> (Edit: granted, if all USD were owned by a single entity, the likelihood that such a policy would be revoked is much, much higher.)

If all of USD were owned by a single entity, the US Government just prints more. They will always have that power. That may cause inflation effects that they would be concerned about in the long term, but they have an immediate reaction lever to increase the monetary supply in such a (weird) hypothetical. (Though the correspondence between monetary supply and long-term inflation has always been much more theoretical "cause-and-effect" rather than showing practical, real world correlation much less "cause-and-effect". Especially this side of the Gold Standard the practical relationship between monetary supply and inflation is incredibly complex, and while you will find many people still presume an inflationary relationship the practical effects have been much weirder. [There are times in recent US history where USD monetary supply was at all time highs and inflation at all time lows.])

(Unless you hypothesizing an even weirder hypothetical where the monetary supply is increased by the US Government just handing the dollars to the single USD dollar holder and hoping that provides incentive to "trickle down" dollars back to everyone, but there's very little anyone can do with the onion of dumb in that weird hypothetical.)