The problem is that they used the XR aspect of it to argue (evidently without basis) that patients would not become addicted to it. There was loads of lobbying

The problem is that they used the XR aspect of it to argue (evidently without basis) that patients would not become addicted to it. There was loads of lobbying of the FDA/DEA, sending doctors to seminars in Hawaii, I even remember numerous op-eds in the NYT arguing that doctors were committing malpractice for undertreating pain. This led to the rise of the Pain Management Clinic, which primarily existed to prescribe opioids. Without the FDA/DEA lobbying by Purdue, these clinics would have been shut down by the DEA for prescribing too many opioids. The message that this huge PR/Sales/Lobbying effort was sending was: XR opioids have a low addiction potential, and not prescribing them, or preventing them from being prescribed is malpractice and insensitive to patients that are in pain. I don't doubt that many fewer people are in significant pain now, but we also have something like 4% of the entire U.S. population addicted to opioids.