There is absolutely not reason that the government should have abdicated its core function and allowed a monopoly effectively have a license to print the dollar bills and rent them out for a cut from ever single economic transaction.
Imagine if the government had suggested that in addition to all the other criminal extortions called taxes, when you use dollar bills to purchase something, you have to pay a 3% dollar-bill-usage surcharge every time a bill changes hands.
But it was obfuscated that this constant drain and fraud was being perpetrated because the whole system became extremely financially lucrative to the very people whose responsibility it would have been to stop the crime; so it has continued since. The mob was in control of the police.