I am not writing answer about this or what I think but want to know what other people think about it. We did some research on economy we think it would. We mean one of my friend and me.
We are only layman in the economy so would like views of others
You do not explain why cryptocurrency would cause an economy meltdown. I do not expect that to happen. If cryptocurrency starts to affect the economy, things will change but negative aspects for fiat currency driven parts may well be negated by positive changes due to increased use of 'harder' cryptocurrency.
Well there is one of the way we can think. But unrestricted flow of money thorough out the world will also have drastic affect on the market. There may be less impact for already large economy but for the country with lower economy there will be problem.
Now at the moment the nation that have lower GDP have very restrictive way of flowing money outside the country which make except for genuine business transaction the flow of money going out side the country is narrowed. As a result of that the currency devaluation is controlled. If large sum of money move unrestricted the investment in the cryptocurrency will definitely increase and at the moment the cryptocurrency can not be bought with in those country the money from those country will flow out side the country so fast that there may be a problem.
That is our theory may be it will never happen but we think there is a chance and those triggers will affect the whole world. That is our main thinking.