I would rather have the one that was backed by the US government because it is more trusted than gold that could be fake.
As a practical matter, the government doesn’t back the paper currency either.
If you get stuck with a fake $100 bill, nobody will reimburse you.
The currency is valuable in part because it is useful to pay taxes. As people borrow from banks, more currency is loaned into existence. It’s more complicated than that, but that’s kind of how it works.
Understandable; it just isn’t universal.