with crystal meth the statistics say, that only a few percent (we’re talking 1-2%) get addicted.

Couldn’t find the numbers on meth specifically but I’m highly skeptical.

70% of users who try an illegal drug before age 13 develop a substance abuse disorder within the next 7 years compared to 27% of those who try an illegal drug after age 17.

25.4% of illegal drug users have a drug disorder.

I’d argue that any form of self medication is inherently unhealthy, and free access to legal substances doesn’t fix that. Some people are able to navigate it responsibly but it’s not possible for most people.

The human brain is a complex soup of chemicals and electrical impulses, altering it with a substance won’t result in an objective self assessment of the effects.

Taking your example, plenty of normal and reasonably happy people get addicted to opiods. The first experiences are on such a different scale to regular chemical pleasure your brain generates that it alters your perception of normal feelings.

If you ask someone to compare that high to normal life before or after, they’ll tell you they never experienced “true” happiness before.

There are real, observable, permanent changes to brain structure from drug use. I don’t think that type of change should be taken lightly with personal experimentation. It should have the same scrutiny and medical guardrails that we give other permanent body choices.

For anyone interested, some reading on heroin’s impact on the brain