I feel like when I traveled to Asia, I didn't see any of that. I don't think it's because of better individual self-control (plenty of other addictions, like gambling, alcohol or smoking). But isn't there like death penalty for drug traffickers there? Is that the only effective deterrent?

Harsh perhaps, but if we look at outcomes, the current situation kills a lot of people and wastes a lot of lives. I can see how some people would think "don't administer narcan to addicts" but I don't think that it's fair to attribute addictive behaviors entirely to the user. Someone is selling them the stuff and know full well the amorality of it. That said, creating negative consequences for users before addiction takes place can also create the right incentive structure to avoid mass addiction such as what we're seeing in both cities and countryside in the US.