It is not illegal for individuals to speculate in cryptocurrencies in China. The policy attitude is "all business is banned, risk is borne by the individual", and it is not illegal for individuals to hold and trade cryptocurrencies.
However, it is illegal to use payment institutions to make RMB deposits and withdrawals (bank Alipay WeChat transfers, etc.), which violates the regulations of the central bank, because the central bank twice required financial payment institutions not to provide payment and settlement services for virtual currency transactions in January 2018 and June 2021.
However, the central bank is not a legislative body, nor is it a law enforcement agency. Even if the user violates the regulations, the central bank can only require the financial payment institution to deactivate your card number (not the counter), which is not illegal. This deactivation is for your card number, not you. In other words, you can cancel the card and apply for a new one. The new card is not subject to any restrictions.