The government-backed crypto can crash the entire market but the possibility of happening odds is unlikely. Zero price means there is no buyer or seller, at least we have a few decades with this technological model, I think so.
Maybe. But knowing that Gold has remained used by people worldwide despite the launch of physical cash, it looks very unlikely crypto will disappear from existence with the emergence of a government-backed digital currency. Decentralized cryptocurrencies will always be valuable (especially Bitcoin) because of their censorship-resistant qualities. No one can freeze your account or seize your assets unlike a bank account. That's one of the many reasons why some people continue to support crypto above anything else. Of course, we have the issue of price volatility which makes crypto useless as digital cash (only practical as a store of value). But it'll never go to zero as long as there are businesses, merchants, and individuals supporting it worldwide.
The only cryptocurrencies that will go to zero are those unable to provide real use cases for the mainstream world. There are so many useless altcoins that are simply copies of other prominent cryptocurrencies within the Blockchain space. I believe that most direct forks of Bitcoin will simply go to zero since they're nearly identical to the original cryptocurrency. I'm talking about Bitcoin God, Super Bitcoin, Bitcoin Pizza, and other silly forks created by developers as quick money grabs. But top cryptocurrencies in market cap might never go to zero, as they've focused on building an infrastructure for decentralized finance with usability in mind. As long as a cryptocurrency maintains active development and provides innovation, it'll never head to zero in the future. Just my opinion
