A single raid may not stop the flow of fentanyl into the US, but this arrest is certainly a significant blow to the Sinaloa cartel and a major victory for the rule of law. Mexican authorities worked for six months to put the crime boss behind bars, which demonstrates that effectively pursuing the cartels is possible. Even in the face of cartel gunmen sweeping Sinaloa, the authorities still managed to extract Guzmán.
The US media has an incredibly inaccurate and racialized perspective of the so-called "drug war" in Mexico. Drug trafficking and violence in Mexico have a lot more to do with how criminal networks work in conjunction with the Mexican state than what amounts to occasional military operations against said networks. Even as the US and Mexican governments' response has expanded and militarized over the years, drug smuggling and use in the US have only increased.
Though it is always good to see a criminal like Guzmán get put behind bars, the only reason Mexican authorities conducted this raid was to create good optics for Biden's visit next week. The Mexican government is capable of cracking down on crime, it just only chooses to do so when it's beneficial to its geopolitical interests. As the US is flooded with illicit narcotics from Mexico, the Mexican government is ultimately only interested in optics as opposed to concrete action.