Its more like 30% carteles and 70% corrupt people/politicians, carteles arent that big or even powerful, against the army they have a big disadvantage.
Although the questions should be When hasn't mexico been controlled by corrupt people? My answer is "idk, since Juarez maybe?" I mean, pretty much every term had some sort of corruption in it, after the independence? There was a point where liberals and conservatives were killing each other for the power, Diaz? Dictatorship, 1910-1921? People killing each other again, after that the PRI/PRN was the de facto governing party, their candidates were often called "the uncovered/ the revealed" because once you knew who it was, you knew who your next president would be. It was that way until the 2000's when another party won the election (and then with another candidate the following term) until we went back with the PRI and now a socialist idiot that doesn't know how to do shit.