The Mafia’s grip weakened at the end of the prohibition period compared to what it had been during that period, although the prohibition period let them get their tentacles into things they wouldn’t have otherwise. Getting real means looking at truth even if it contradicts your previous beliefs.
The Mafia moved from one form of crime to more sophisticated forms. The only thing that has weakened it ever has been law enforcement take downs. To think that Mafia does not have a massive and effective organization is naive.