They dont need LLMs to spy on you. Their ad network and google analytics is already everywhere on the internet and mobile.

Nearly half of their users use ad blockers. The AI spyware, on the other hand, bypasses ad blockers and can answer questions like "what was the user up to on Sep 18?" These short summaries will be carefully kept in database, and in a few years Google will have a nearly perfect cognitive model of all their users. The value of such data is hard to measure. Every big advertiser or a tyrant would sell their soul to understand how to manipulate their populace better. You can't have this with today's ad networks.