I think this is a legitimate attempt to 'fix' the internet. It seems only very basic information on interactions with ads is recorded by the browser, and then it is anonymised. As an example, the advertiser should only receive counts of how many people bought a product after seeing a particular ad. I don't think they can see what webpage anyone in particular came from, but maybe they can see that: 11% percentage of visitors came from example.com/some-page

Presumably the anonymised data is only provided once the pool is fairly large and wouldn't show 100% of visitors came from cornhub when you only had one visitor 🤷‍♂️ Obviously websites will always see an IP address.

The idea is for this to substitute for traditional, more invasive, tracking. I think it may one day achieve that.

A warning though: I only just started reading about this.