The approach the major browsers (except Firefox) have been taking is to provide new APIs that allow ad-related functionality without individual-level tracking (and then try to block cross-site tracking). Examples:
This seems like a good place to put it, to me. Users choose their browsers, and browsers are generally open source. This still does not do anything about same-site tracking, but in that case users are choosing which sites they interact with. Also, while this is being built with cross site tracking use cases in mind, I would like to see it built in a way where individual sites can also use it to demonstrate that their data collection is private.
The approach the major browsers (except Firefox) have been taking is to provide new APIs that allow ad-related functionality without individual-level tracking (and then try to block cross-site tracking). Examples:
Apple/Safari has Privacy-Preserving Ad Click Attribution to support conversion tracking
Microsoft/Edge has Parakeet to support remarketing
Google/Chrome has the Trust Token API for Spam/Fraud/DoS, and various other Privacy Sandbox Proposals
This seems like a good place to put it, to me. Users choose their browsers, and browsers are generally open source. This still does not do anything about same-site tracking, but in that case users are choosing which sites they interact with. Also, while this is being built with cross site tracking use cases in mind, I would like to see it built in a way where individual sites can also use it to demonstrate that their data collection is private.