The american cosa nostra will come with new ways to earn illegal money, its a new century. Sure they got huge blows from the FBI and the government, but still they manage to survive and reorganize. And i am sure new talented soldiers and captains will rise to fill the ranks. And perhaps bosses, not like Gambino, Lucchese or Gigante but they will be there. Internet and other technological things work in both ways, legal and not legal.

And not to forget the size of the current status of the 5 families, they still have above 400 made men.