Bitcoin isn't like real money though. Take the US dollar - whatever happens, something like 300 million people and tens of millions of companies will still need

Bitcoin isn't like real money though. Take the US dollar - whatever happens, something like 300 million people and tens of millions of companies will still need to pay taxes in that currency. That's a big baseline demand, before you even consider the goods and services available in the economy that can be bought with US dollars. Whereas everybody trading bitcoin or accepting it as a payment method could switch to a different cryptocurrency tomorrow...