How is the system proposed by GP authoritarian? It's not actually giving away any real PII. We could just argue that it would make Internet less usable for "illegal" immigrants who don't have a Gov ID - whcih can be seen as a problem already in itself, but still doesn't make that solution "authoritarian".
If you're willing to admit this is entirely possible from a technical standpoint, there's a separate question about how useful/valuable it is.
Making it harder for children to access extreme pornographic or violent content seems useful to me. Many advertisers want to be able to say they've shown ads to a human not a bot. Humans in WEIRD* countries have more valuable eyeballs than humans in the developing world.
If you don't solve for those use-cases in a privacy preserving way, adtech will do it in an intrusive way - which is what Google are doing in the OP.
*"Western, Educated, Industrialized, Rich, and Democratic"