Yeah, you argument about pragmatism resonates with me. If all tracking was turned off over night that will break a lot of streams of revenue that many businesses/sites online rely on. Those businesses has grown because it has been possible and profitable to track you every step online. That does not mean that system needs to be preserved, or replaced with something similar. Markets adapt, we don’t have to help this business find new ways to make money.

And also, cross-site tracking is not necessary to do advertising, it just make is more cost efficient. I don’t accept the argument that they need my behavior data to have a working business.

Ads in newspapers have worked historically without the tracking. (Newspapers a hard time now though competing with the more profitable online ad business)

Also cookies have other functions aside from tracking your behavior, while this new feature only benefits ad/product analysis, with no direct benefit to the user of the browser. It’s essentially giving away information about my behavior, albeit without telling them who I am. (Indirectly users might benefit from having more ad-supported services online)

But sure, Mozilla is free to do what they want. I still like and use Firefox.