There is big possibility that bitcoin will also crash. People invest in bitcoin because they have money from their "saving". When global economy crash the price of commodities will be very expensive or people income will be reduced and of course this will influence the investment rate of people.
with current global economic crisis, where mighty dollar is alone, it will make the exchange rate against dollar even higher, of course this will add to bugjet investors to buy dollars before they are invested in btc
Yes I agree the price should go up during a crash but think of why the price goes up normally, because people buy bitcoin more than they sell bitcoin, during a crash people will sell their bitcoins to cover the expenses caused by the crash, so there won't be any increase by that method.
I think the slow decline of dollar due to inflation is acceptable and understandable but during a crash it is really hard to get people to buy or at least hold. We need to take a look at the factors that causes bitcoin to increase and by all means all factors show that if there was a global economic crash the price would go down as well.
If you can purchase stuff for cheaper in fiat that means the price of bitcoin will get lower as well. Don't get me wrong 1 bitcoin that is 6 thousand dollars right now may not buy as much as a 1 bitcoin at 3 thousand during a crash because everything will be cheaper and your 3 thousand will be more valuable.