IF the whole world ban BTC at first BTC will Crash very hard but only for a few month, Demand will be increased while there will be no Legal Seller, All trade will go to undergrand and Black market and illegal traffic, sellers will start to selling BTC 50 X more than current price. BTC will be more expensive, As simple as that,
That was an answer for these who said BTC will die if whole world Ban it, So no BTC never Die.
Its not really the worth of Bitcoin that will increase but the fees that those that are selling it will be charging. If you want to buy $1,000 worth of cryptocurrency, since its illegal those people are going to charge you a lot of money to carry out the transaction, but you wouldnt be getting that same amount you paid; you might pay $1,500 and only $900 or $1000.
I dont really think that would be good because only bad people in the dark web will be buying and making use of it for their transactions, and other people who are afraid of the law would stay clear from it. So its not really a good idea and Im not praying for that to happen, I prefer that more and more countries keep declaring it legal.