China has blocked a lot of things besides Bitcoin/Cryptocurrency. Call it popular search engines like Google, social media like Whatsapp, Facebook, even TikTok, which is known as a social media made in China. And they never worry about that, because they already have something to replace all that things.
They have a Great Firewall but it does work as they wanted and can not block all Chinese to access the Internet resources from other nations like Western. The pandemic shows that if their citizens want, they can break the governmental restrictions to access to other resources with freedom of speech.
I'm sure they've thought about the impact of a ban on Cryptocurrency activities. With their technology and economic strategy, it seems that China has nothing to lose by banning all Cryptocurrency.
They can ban Bitcoin or Cryptocurrency mining in a short period but they won't keep it lasting too long. If they see the whole world accept Bitcoin and Cryptocurrency mining, they will not self-kill themselves by banning that industry.
They know their nations have abundant energy resources for it and they can get profit from it too by running Bitcoin and cryptocurrency mining. China is a nation that care most about financial profit, economical benefit, their governmental power so if they see great opportunities, they will not skip it.
I don't exclude scenarios in future when many governments will engage in Bitcoin and cryptocurrency mining.