I wouldn't want to live next to El Chapo and I didn't talk about typical neighbourhood drug dealer. It's about scale. There are many people I don't like, some of them even politicians but I wouldn't suggest harming them in any way.
I'm sorry ,it's just so damn easy for you to volunteer other peoples lives to be collateral damage in an extra judicial killing when you know statistically it won't be you.
If I had no other chance but to live near such criminals, I would try to suicide-bomb them, but that would probably be too hard and counter-productive because of layers of security with which those people surround. What would YOU do if you had to live near such criminals?
You many want to research a bit how these cartels work. Kids grow around down, they are part of the society around them and a central point of it. They couldn't survive any other way.
You have a kid that grew up thinking (not without a reason) that there's no better way than that do what the boss says. It will die to protect him. "Oh that kid is just a criminal, kill him!". In many cases, places where these cartels thrive are places where they locally can do better job than the government does.
I don't think that taking out the highest figure simply solves the problem. It wouldn't change much on the long run and on the short run highly increase the violence.
But more importantly, it seems extremely rare, that you could make a world a better place simply by killing somebody or a bunch of people. It's easy to think that, and a HN comment is too short to dive into that, but when you take time to think everything through, it seems far from obvious.