Mass, widespread, unchecked use and subsequent dumping of the chemical was phased out because that practice was understood to be harmful to people and the environment. The fact that it is now used in a controlled and regulated manner is entirely different. You either missed this nuance, or you are deliberately being obtuse to make a point that "it's technically still used" which, obviously, is true, and also doesn't contradict the fact that it was phased out in the 70s once found to be poisonous.