This is a false–albeit common–misunderstanding. "Federal statutes do not require a seller to accept cash as a form of legal tender for payment of goods or services that were rendered. Thus, businesses may establish their own policies regarding whether they will accept cash as legal tender" [1].
Yeah you can. Tell that to all the stores in rougher neighborhoods that kept getting held up at gunpoint for the cash in the register, so they stopped taking cash. Bit harder to get money out of a stolen credit card terminal.
And if your "near magical genie" can make an operate military equipment, you don't have to respect existing authorities anymore.
Basically, the "AI maximalism" scenario kicks the legs out from under all these concepts and social institutions you're relying on.
> Most of the developed world already has magical genies - certainly an overwhelming majority of people on HN earn enough to have LLM subs that build code, 3D Printers that print physical things.
Not like in the scenario we're discussing. Whatever "magical genies" we already have are incomplete and need operators or have serious quality problems. Most of us depend on those limitations for our livelihoods, and those limitations also give levers to control them.
> You just cannot live in a vacuum. If you could subsist entirely on cheetos and figured out how to make an entire lifetime's supply of cheetos, after N days of watching Netflix, arguing on HN, raising chickens and goats, one day you will want to go and talk to a human.
An oligarch with the "near magical genie" could easily build a town of 5,000 to satisfy his needs to "talk to a human."
Minor side note: this is true only for repayment of debts. Some local jurisdictions require private parties to accept cash for new purchases, but there's no federal requirement to do so.
I'm also interested what this "entity in charge" does? and why would it do anything at all?
Absolutely untrue. Outside of some local laws governing cash at retail you're under no general obligation to trade with someone if you only want payment in cybertrucks and all they've got is dollars.