That's a good point. It depends on how you see this, as either a weakness or a strength. Chapo wasn't fighting over territories(he wasn't replacing the state) in the proper sense of the word. He was fighting over drug corridors, which really means distribution rights. Carillo Fuentes bypassed all of that.
The level of violence in Mexico doesn't mean the cartels are strong, it means the cartels are weak. They have to use violence, they have to spend hundreds of millions if not billions into recruiting, paying and arming people, because they can't get their way otherwise. The G is too strong, the seizures are growing, it's getting harder and harder to make a profit so the market is shrinking. That's why they're fighting amongst themselves for a larger piece of a smaller pie. I would guess the majority of a cartel's income is spent on police/government bribes and maintaining their armies.
The Russian and Italian mobs are stronger than the cartels, because they make just as much money but with far, far less violence, and they have far more political influence.