In many countries the VPN usage is sky high and people keep going to websites the government has banned. That is just one example, I have seen bans on all kinds of tech related stuff in some countries that people keep finding solutions to by pass that ban.
China is a huge country and yes if they allowed people to use coins the way they want and let them be the bitcoin deal would have been a lot bigger there however no matter how much you ban crypto, it is not something you can just go and ban, the things you ban are the exchanges and people can still trade OTC some how.
China blocked China based cryptocurrency exchanges from selling crypto for Chinese Yuan. They are allowed to trade crypto to crypto and you can buy and sell for Chinese Yuan as long as it is not from an exchange based in China.
They are basically trying to regulate the crypto environment in their country in such a way that it doesn't effect their internal economy as it helps ultra rich to transact in overseas market. They have been putting such regualtions on online sphere for a long time now.