the consensus of market participants is an important factor in determining the value of Bitcoin. The value of any currency, including Bitcoin, is ultimately determined by what people are willing to pay for it. If a large number of people agree that Bitcoin has value and are willing to buy and sell it at a certain price, then it will have that value. If the consensus of market participants changes and they no longer believe that Bitcoin has value, then its value will decrease. However, it is important to note that the value of Bitcoin is not solely determined by consensus.
Anyway It is unlikely that Bitcoin, or any other digital currency, would be able to survive a nuclear war. In such an event, most of the infrastructure that supports the digital economy, including the internet and electrical grids, would likely be severely damaged or destroyed. Without these fundamental technologies, it would be nearly impossible for people to access their Bitcoin wallets or transact with the digital currency. Even if some individuals were able to hold on to their Bitcoin, there would likely be no one to buy or sell it with, and it would therefore have no value.