Chinese Yuan before the ban accounted for 70% of all Bitcoin trade. After the ban it's less than 1%.
That was back in September. Bitcoin was below $4000 back in September. Crypto destroyed? The facts say no. The history says no. It's not going to happen.
Also privacy coins are able to break through the Chinese Great Firewall. Also, decentralized exchanges cannot be banned. And there's plenty of those.
Like it or not, crypto is here to stay.