When somebody finally stops drinking, the story usually includes one friend who quietly stopped suggesting pubs. No speech, no ultimatum. Just a standing invitation to a Sunday walk that went unaccepted for two years.
Transformation belongs to the person doing it.
What is available to everybody else is the surrounding conditions - making the better option slightly easier to reach, and being unembarrassing about it.
Nobody has changed anything important because they were told to. Plenty have changed because somebody left a door open long enough.