Mexico needs to do like Bukele. Round up every cartel affilated person in the population, and imprison them for life. This requires imprisoning them for life simply for known affiliation with the cartels, without the usual process of trial and conviction of a specific crime.
If this is not done, the cartels will rule, and Mexico will continue to be a hellhole like El Salvador used to be. The cartel members should be considered like pirates in the old days: enemies of humanity to be executed immediately, or imprisoned immediately for life as the modern alternative.