A certificate from the government that gets revoked when you commit a crime. Or are accused of a crime. That can track every single thing you so online. All of your speech online, which is most of everyone’s speech, is permanently stored and analyzed.
The government doesn't need to know which services you use and which accounts are yours. The service doesn't need to know who you are, only that you are a unique human.
But yes, as I said, I hate the idea. Was asking for other solutions.