No government has yet regulated online services to require financial KYC compliance afaik, other than banking services which are already covered by ‘banking’. To the best of my understanding, the regulations about age verification don’t tend to mandate forever storage of the identity data, only storage of the verification outcome — even if business misrepresent that in order to harvest, train, aggregate, resell. (Whatever China is doing is not KYC: the government performs the Know verb in those cases, rather than the business.)

KYC for financial institutions is orthogonal and stems from different laws.