Browser based solution not mandated by law but made by the industry wouldn't work, because all 4 major browser vendor makes significant revenues from Ads. At a

Browser based solution not mandated by law but made by the industry wouldn't work, because all 4 major browser vendor makes significant revenues from Ads. At a time a solution appeared with "do not track", and we ended up with the industry making sure it was as toothless as possible, opt-in, and google pushing hard to control the browser market.