Imagine if I actually linked to cartel machete execution videos right here on HN just to give you some real examples.
The cartels are only powerful because they have the money to be powerful. I can't imagine selling organs would be nearly as lucrative.
I mean Pablo Escobar was worth $30 billion dollars in 1993, which is around $51 billion today. For reference, Gates is worth around $86 billion, and Gates operates within the law while Escobar could buy off entire countries and was, for the longest time, immune from real prosecution. You can't buy that by selling organs.