When you say crypto does it mean bitcoin only or any coins too? If you are referring to bitcoin then I think it is impossible because bitcoin has a lot of investors and it is growing every day. Bitcoin is very successful for many years now and it has established it's name already. I know anything can happen, it's the reality but if the price will go down it won't go as low as zero. On the other note, the only coins that I see that would go zero are those shitcoins who did nothing but just to ruin cryptocurrency image.
I'm referring to all cryptocurrencies being traded on the market today (Bitcoin and altcoins). As for Bitcoin, I doubt it'll ever go to zero because of its limited supply and widespread acceptance within the mainstream world. But altcoins can go to zero sometime in the future, if they're unable to deliver real use cases for everyday people. Most of the useless coins on the market with no active development or innovation will die, while very few will be able to retain their value on the crypto market. I believe that altcoins like Ethereum, Monero, Zcash, Dash, and even Litecoin will never go to zero as they're supported by their communities. Not to mention, these coins are actively developed and maintained by prominent developers in the industry. But as with anything, if these cryptocurrencies lose interest/demand from everyday people, they'll fail in the long run.
I've found it odd that Ethereum's Vitalik Buterin stated that "crypto will go to zero" in the future. After all, crypto has been able to survive after 11 years since inception. If crypto has gotten this far, I believe that it could reach new heights over time. With many people joining the crypto/Blockchain ecosystem, it's very unlikely that crypto will go to zero anytime soon. But as it's said in the real world, "nothing lasts forever". We should be prepared for the worst if the market starts to decline massively in price like never before. Just my opinion
