They're prediction are fine if that was really based on their study. But that just always doesn't mean for the truth. ere's still a lot of factors to be considered before saying such thing. Th

It's always possible for any currency to fall to zero value or be replaced by other currency reagardless if they are crypto or not. In the case of bitcoin, just like what other users mentioned above, the probabilty of bitcoin crashing to zero value is near to zero, as this coin is strong and there are a lot of people that are supporting it. That's why it is unlikely for it to have zero value.

Can it be replaced by other cryptocurrency? Yes, but again, it's unlikely, the coin should have a massive adoption(more than bitcoin had), if that happened, that just means that cryptocurrency is way better to bitcoin technology not just as cryptocurrency.