Because of the anonymity of 12 step meetings there is no accurate way to measure their success. I spent a few years going to Alanon meetings and attended a number of open AA meeting over the years. With both groups I noted lay people with no degrees or training handing out simplistic advice. The groups do not deal with the underlying reasons why a person chooses to self medicate with a substance. I also noticed that a large majority of individuals who have followed AA and claim AA is responsible for their sobriety don’t own their own efforts to overcome their addictions. Many do make AA the focus of their own lives and those of their family, literally trading one dependency for another.
There are many paths up the mountain.