It's never the drugs that make a society erode; it's a symptom. If you have a big drug problem in a country, most likely it's related to much bigger issues at the core. Like in the Opium Wars, it was the British Empire that basically drugged China as a means to get what they want. It's not like they discovered drugs and then just stopped doing anything else; we humans had drugs and used drugs since we know about them.

Some argue this tactic is still very much in use today, hence the fentanyl crisis, which seems to be fueled by China. It's a destabilizing tactic. That's also part of why China and other Asian countries are so strict because they know firsthand the effectiveness of literally drugging your foe to gain an advantage. This does not mean China and co do not have their own drug market; they have a pretty vivid drug scene.

Also, as an example, Japan or China, yeah, sure, you can't buy weed; they will basically curb-stop you legally. But you can drink as much alcohol as you want, smoke as much tobacco as you want, and drink as many caffeine drinks as you want. These are all recreational drugs with a much higher impact on society than weed, yet they are totally legal and accepted by everyone or are even traditional.