What different approach could be taken? Everyone knows that using drugs is bad but they do it anyway so education doesn't work. Treatment has failed miserably with less than 50% completing treatment programs and less than 50% who do complete treatment staying off drugs. All you can do is try to stop the supply.
The first thing is to recognize the reality of the situation. Most drug users do not cause damage to society. I believe it's single digits across all substances. Stop trying to arrest drug users, and focus your attention on the small number that are problematic users.
Our treatment programs should be changed. Drug abuse is often times a reflection of a withdrawal from society. Portugal decided to try and focus on
societal reintegration. This includes vocational training, as a person with a career is far less likely to continue abusing drugs.
We need to focus more on harm reduction immediately. Needle exchange, clean injection sites, etc. This helps prevent the spread of HIV, hepatitis, and other diseases that spread through shared needles.
Lastly, we need to allow for legalized drug sales. That's the only way to destroy the cartels. It would also ensure safer drugs for all drug users, those that are problematic and not problematic.
We also need to allow better research into the medicinal benefits of LSD, MDMA, Ketamine, and psilocybin. Those drugs have shown tremendous promise for treatment of depression, PTSD, and other mental illnesses. It's shameful to force people to suffer through those conditions when we have better options.
Unfortunately, this isn't going to happen yet. We'll continue the same strategy that hasn't worked and will never work.