AI can put together all that personal data and create very detailed profiles on everyone, automatically. From that data, an Ai can add a bunch of attributes that are very likely to be true as well, based on what the person is doing every day, working, education, gender, social life, mobile data location, bills etc etc.
This is like having a person follow every user around 24 hours per day, combined with a psychologist to interpret and predict the future.
It’s worth a lot of money to advertisers of course.
You can set up wireguard vpn on a tiny instance in Amazon or Google, and bounce traffic through that one. Then you control what gets logged (Amazon may have logs over all outgoing connections from all instances somewhere though).
You can even make it change it’s public ip every day if you want.