There are some very serious authors that have tackled this topic, I would check out Anabel Hernandez and her work on the history of Mexican cartels and their relationship with Mexican business and politics. https://www.amazon.com/Narcoland-Mexican-Lords-Their-Godfathers/dp/1781682968
There is a TON of shows/movies about Mexican cartels, almost all very divorced from reality and just there to glorify the cartel leaders and/or henchmen, mass media loves that. I avoid them.
One decent documentary I found was Cartel Land on Netflix that covered a specific point in time in a region of Mexico.
Just to clarify, cartels don't "control Mexico". There are some parts of the rural countryside in a handful of States that they effectively control. And even there, when the military/marines drop in they scatter like rats. Problem is, they always come back, the business is too good to disappear. Very sad really.
The current troubles Mexico has with Cartel violence started in 2006 when the federal government started a poorly named and planned "War on Narcos". The homicide rate more than tripled in the next 6 years and has steadily gone up every year since then. Btw, most of the architects of that war are in jail in the US awaiting trial for, you guessed it, working for the cartels.