The current fiat system consists of different systems that are interdependent through the defects of the current main stream economists, and the fact that central banks cooperate.
It's a flaw that central banks cooperate?
A new thing is the loss of anonymity, the anonymity is a requirement for free individuals who comprise the free market system.
For all intents and purposes, once the mainstream adopts bitcoin, anonymity will be next to nonexistent. Not because there'll be any changes made to Bitcoin. But bitcoins pseudoanonomyity only works for people now who understand what it is and isn't and take active steps to remain anonymous. For the mainstream, the record keeping of the blockchain will yield the same, if not more, information as is collected by banks and credit card issuers. Except, instead of it being only in the hands of those companies, everyones transactions will be out in the open for EVERYONE to examine.
I don't see Bitcoin as being the winner in that case. Yes, right now, small group of knowledgable users, yes, it wins, but only for people who proactively take steps to preserve it.
Your understanding of the historic international trade system, that worked for centuries, is totally off the mark. The system that worked for centuries, was decentralized. In fact, the free market economy is decentralized by definition.
The defects of the current system:
Fiat systems are centralized, because there is one entity that issues money. They have each worked a few years, then collapsed.
The current fiat system consists of different systems that are interdependent through the defects of the current main stream economists, and the fact that central banks cooperate.
A new thing is the loss of anonymity, the anonymity is a requirement for free individuals who comprise the free market system.
A new thing is government control of the payment system, enabling governments to step in and destroy free trade between any two free actors. They can do this without entertaining the government law system.
We have never in history had a basically world wide fiat system, never has a fiat system inflated to the current degree without imploding.
So we are in desperate need for a new system. Sadly, bitcoin is years away from having the necessary expansion to be able to take over. Brace yourself for a period of money system confusion, as new systems are brought about from people who understand nothing.
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When the central banks cooperate, there are not 100+ fiat systems any more, rather one, meaning more centralization.
The degree of anonymity in bitcoin depends on how many of the addresses can be linked to individuals. When most addresses are linked to individuals, many of the others can, with some work, be traced to the trade partners of the known individuals. When just a few addresses have known owners, the remaining addresses can not so easily be traced to individuals.
I think there is a good chance that the future situation will be that only a few addresses have known owners, therefore the system as a whole will be largely anonymous.