I don't know the full story of El Chapo or seen any of the documentaries/movies. However, I'm assuming he committed the same crimes in Mexico. Why would he be extradited to the US without facing trial in Mexico? Even if Mexico was too corrupt and he may escape, isn't it odd that he was sent across the border before being tried in his own country?
It's not odd to extradite people who are accused of crimes. The US has extradition treaties with many countries: see List of United States extradition treaties - Wikipedia. Extraditions are also recognized by international law: Extradition - Wikipedia
As for El Chapo, the reason for his extradition is
The decision to extradite Mr. Guzmán was an about-face for the Mexican government, which once claimed that he would serve his long sentence in Mexico first. However, after his Houdini-like escape in 2015, when his associates tunneled him out of Mexico’s most secure prison, officials began to reconsider.... When he was recaptured early last year, after one of Mexico’s most exhaustive manhunts, the government publicly said it would allow the extradition of Mr. Guzmán, thus relieving itself of the potential embarrassment of another escape and preventing further souring of its relationship with the United States. El Chapo, Mexican Drug Kingpin, Is Extradited to U.S. - The New York Times