The problem is that there's a literally a 3-trillion-dollar business depending on the difficulty of rejecting tracking. The inability to easily reject tracking

The problem is that there's a literally a 3-trillion-dollar business depending on the difficulty of rejecting tracking. The inability to easily reject tracking cookies is not a technical problem. It's a problem of lobbying and malicious compliance by megacorporations living off web surveillance. They will subvert (P3P), ignore (DNT), or replace (FLoC) every technology that makes it easy to reject tracking cookies. They will fight every law and smear every institution that tries to mandate use of any easy tracking-rejecting technology.