Actually, the quantity of USD will increase, but the value of them will decrease. At least that's the theory.
You can have deflation from a banking/investment perspective, since debt is claimed as an asset (I learned that the hard way in 2008 when flenser's millions became flenser's thousands in just under 48 hours), but the actual quantity of USD generated will continue to increase for the "long run" as Keynes would say.
On UN controlled crypto, not bloody likely. Crypto is about choice, and no one is going to choose a currency that can be easily taxed. The one thing the USD has going for it is Americans have to use it to pay taxes. Without that imposed theft, the dollar would have gone the way of the Continental decades ago.
You misunderstand, and are not familiar with Keynes' work.
We are moving to a world where the use of national currencies as reserve currencies will end. Instead, we will have something similar to Keynes' Bancor.
Keynes' argued that competitive currency devaluation was the primary cause of World War II, in that both Germany and Japan were resource poor and export dependent. They devalued their currency (expanded their national money supply) to gain a competitive currency advantage on the global market. Domestically in germany, this was also to reduce their war indemnity, but that was a side point.
The Bancor has many variables, but increasing your money supply beyond what is considered reasonable (and the variables include population growth, natural resources, necessity of export industry, etc) would result in the exchange rate of your national domestic currency for Bancors changing to prevent a competitive currency devaluation scenario.
Blockchain is part of establishing a global accounting system to track all exchanges and to insure relative stability of the global market.
Your ideology about blockchain "it's about choice" is irrelevant. In time, cryptocurrencies will be banned just as forex trading was before 1976.
In the not so distance future, foreign exchange in anything other than Bancors or barter will be illegal.
As for the difference between currencies and collectables like comic books and bitcoin you are half right.
Money is about establishment of sovereignty, and part of that is the ruling sovereignty issuing currency and demanding the citizens pay taxes in that currency. But civilization couldn't have begun on that alone. You are missing the other key element.
Courts only adjudicate debts in the currency issued by the ruling sovereignty.
This is why all US currency, and others, state that they are redeemable for "all debts public and private". Private debts are those adjudicated in civil court.
