What would happen to Bitcoin’s value if all countries banned crypto exchanges together ? Can it survive such an action ?
Have you forgotten there is a decentralized exchange?
If countries ban crypto exchange then dex won't be included, it can still be running as long as there are strong believers of crypto, then the price will be affected within some couple of months while get to be recovered after the heavy news.
No news had ever broken the price of Bitcoin down forever, it fluctuates downward for some time and rise again to the highest peak no matter what.