As long as people believe in the prospects of cryptocurrency, it will not go to zero, as it is constantly being invested by new investors, and blockchain technology itself is very promising
for now crypto still has many users plus there are still many people who want to know more about crypto. and for the possibility that the zero value crypto is very difficult as long as development continues to run within the crypto
Crypto cannot be zero because the whole world is interested in technology as this is modern era in which people will love to engage in crypto because it is best source of income for most of the people in the world and also there are a lot of investors who has invested a big amount of their money so they will not want crypto value to be zero, as the time pass by the crypto users are increasing.
When we are speaking about today, I doubt that crypto will become zero, as we cannot control the number of users anymore, the number of demand now is increasing rapidly, but as per the question, the crypto will become zero once all countries will banned the use of cryptocurrency in their respective countries which I doubt will happen.