In 2020, the EU reported 5800 drug overdose deaths in a population of 440 million. The same year, the United States, with a population of 330 million, reported 68 000 drug overdose deaths.
Then I guess in your world the cartels can just bring in any amount of narcotics and Americans would have no option to buy it all...
The two things go hand in hand. Cartels couldn't sell huge amounts of narcotics if America didn't have a drug problem and part of the reason America has a drug problem is because the cartels make it easy to have access to drugs. You can try to fix this by limiting the amount of drugs from the cartels or by fixing the underlying problems that drive people to do drugs.
It's a very American approach to blame the cartels for the drug problem because admitting fault on your side is inconceivable and actually fixing that is socialism.