I think you can make a distinction between highly disciplined and organized Mafia groups (not just LCN, but also the Yakuza, Russian Mafiya, the Mexican drug cartels, etc.) and far less disciplined street gangs, and it doesn't just have to be about scale. I am not a sociologist or a criminalogist so there might be an academic threshold I am not aware of, but to me what separates something like the LCN or Yakuza from your typical youth gang in a neighborhood is that the former have very clear hierarchies, strict internal processes for handling matters major to mundane and are capable (and not just willing) of handling more "advanced" forms of crime. The Fruit Town Pirus in Compton, CA may be more than willing to transport heroin from Southeast Asia and then market it wholesale, but they don't have the knowledge, means or connection to do that. They end up on the distribution side of things.

It's interesting you mention the 'Ndrangheta and Camorra because, based on what I've read about them, even though they are engaged in drug trafficking there is also a lot about them that resembles the undisciplined, much more overtly violent neighborhood gangs I mentioned above. In the US, while the LCN may have started out as being very community-oriented and centered around family networks, it's obviously gone much more underground and, as IvyLeague said, has diversified. With the 'Ndrangheta and Camorra, seeing as they have their roots as regional support groups due to a state that either neglected or antagonized them, they are much more open and a fixture in certain parts of southern Italy. They exist both as the shadowy mob we know here in the USA as well as the more obvious thugs walking around with guns, looking menacing. You watch something like Gomorrah and the posturing the kids do to imitate the Camorra, it's much more like how many kids in the USA imitate in appearance and in petty crime the gangbangers they've come to idolize in popular culture. And those gangbangers in turn aspire to imitate the higher tier of crime above them, looking up to Lucky Luciano, Al Capone, John Gotti, etc.

I totally agree that we shouldn't glamorize criminals or what they do but to blur all lines for the sake of staking a moral claim that "all lowlifes are the same" seems to be a bit excessive. Academics or even armchair scholars can study something, form categories and draw distinctions without romanticizing what it is they are studying.