You could very easily build the system to perform the age check without logging it to the user’s ID since the check only needs to be performed once to create an account and just block anyone without one from seeing any of the content.

Estonia has digital ID based services and they aren’t China. In fact China despises them because they’ve made the cutting edge in digital public services without having to compromise citizen privacy, which makes China look even worse for going out of their way to invade citizen privacy when it isn’t even necessary to offer the same safety measures and services.