Blocking domains works right now but what if Facebook register a new domain? Or a thousand new domains? Or they proxy traffic through a site owner's domain? What's needed is a way to block Facebook's privacy invasion regardless of the tech they use. That is unlikely to be a problem solved by tech. It needs enough people, including governments, to tell Facebook they're unhappy with Facebook's activity.
As far as the cross-site tracking goes, they'd actually need to get all the other websites to update the facebook JS code they include, and it would only work until the tracking blockers updated their lists again.
I agree that tech is the wrong place to be solving this problem, but it can work in a rather cludgy way.
