knives have always been carried, but never for that purpose, - my wife (58) carried one for protection when she was in her 30s and walking home at night. She also wore rings on every finger that could act in a similar way to a knuckle duster. Other women I know carry nail files for protection.
Where the young are concerned, I think, without a doubt, the breakdown of the family unit and home discipline are mainly to blame, and for that, if you look back, the families demise began in 1997,
Yep, Punks, rockers, mods, skinheads,etc etc were all good, law abiding citizens who never went looking for trouble or went around in gangs or carried chains or knives.