Bitcoin is still there, bitcoin's value is still there but it is already useless when all countries shut down echange trading. It will die because of No demand, high demand is important because it will make the price or value more higher. If people already stop using bitcoin it will surely die and it will become commonly useless to all people then the holders of bitcoin face big crisis in their economy. It will surely get them down because of this kind of trouble if bitcoin will be ban in all countries.