With the creation of Bitcoin and other digital money systems before this and afterwards. All of this was created in the private sector. Traditionally most of the fiat money systems were run and created by some branch of a government or public system.
This statement seems wrong to me. Actually most fiat money systems were created by private entities and later on, some of them were nationalized and/or regulated by the governments.
The US federal reserve was basically a bunch of private banks, back in 1913. The first central banks (created centuries ago)were actually private. They were put under government control decades after their initial launch. The bank of England is a great example.
All credit/debit card companies like VISA, Mastercard and American Express are private.
All the digital payment services that are using fiat money are private-Paypal, Skrill, Zelle, Cashapp, Venmo. The list goes on and on.
There's no "private vs. public" dichotomy, when we are talking about financial services. There's actually a symbiotic relationship, the private sector creates the financial innovation, but the government creates the regulation and tries to reduce the amount of financial scams.