I'm Portuguese and can confirm this works pretty well overall.

It's still too strict though - I got convicted of essentially "possession with intent to distribute" just for having ~15g of hashish when I was young and a regular smoker some 15 years ago (the legal limit is 5g). I only got a bit over a year probation and it never showed up on my record, but it was extremely unfair IMO and a traumatic experience - to this day I still have nightmares of being arrested and my home being searched every once in a while, and a big distrust for police and the justice system which will probably never go away.

Decriminalizing drugs wasn't the only thing Portugal did. They virtually force people into rehab. They don't just go around distributing crack pipes like the US.

I think you'd want to look into the Opioid Epidemic.

https://en.wikipedia.org/wiki/Opioid_epidemic

I get the impression America is uniquely vulnerable among the wealthiest nations. Private healthcare providers, a defanged health regulator, and rampant corporate bribery/advertising. Purdue salespeople lobbied doctors directly to prescribe their opioids to patients, while Purdue suppressed knowledge their incredibly addictive nature, and later offloaded blame to the addicts they largely created.

Here's a long overview of the Sackler family and their involvement in creating the opioid epidemic https://www.youtube.com/watch?v=3-dptkIZ7tI