Would btc be liquid ? How would you even send and receive even if you do own the private keys to your coin?
I am aware virtually all other aspects of our lives would be fucked properly more than likely before btc even comes to our mind if this were to happen (unless you were disproportionately invested i.e. majority of your portfolio is crypto). Still It's interesting to consider whether bitcoin really is comparable to gold in this sense - if the world really goes to shit btc aint helping noone. COVID showed us how fragile civilisation is it wouldn't take much...
you cant do anything, and will be worst tragedy if it happen.
you cant compare it with gold, they have different ability, world, and other. people will play which card is the best on that time. and when it come true for long time, people will back to the past, still use fiat, or back to stone.