Why nothing about opioids?

Some quick facts about opioids, including heroin. I have written up a version of this with sources if so desired.

0.) Opioids cause feelings of well-being and euphoria, and usually some sedation (though some can be stimulating). They do not generally cause mental impairment, unless enough are taken to cause one to nod off. Negative side-effects are rare at low doses, but increase as dose does, and can include nausea and constipation.

1.) Most opioids - again, including heroin - are not toxic in any manner*. (Meperidine is a notable exception.) One could be on morphine, for instance, one's entire life, and not suffer ill health effects beyond constipation (usually easily fixed with magnesium).

2.) Opioids are very addictive. No qualifiers here.

3.) Heroin addicts are usually so unhealthy because of drug prohibition, not because of the drug itself. Some of the things heroin is cut with are dangerous in combination with it (like quinine), or just plain dangerous; its manufacture is illegal and there is no quality control; and it is expensive, so addicts engage in behaviors like injection or theft.

4.) Opioid withdrawal will not kill you, and opioids are usually fairly hard to overdose on accidentally. Most heroin "overdoses" are actually due either to what is thought to be a contaminant in the heroin, or due to mixing drugs to make a limited supply of heroin last longer (see #3).

*I have read an article stating they can cause dopaminergic toxicity, which is what rewires your brain to require opioids after using them for a long time. As far as I know, this is reversible, however.

I have a theory that most opioid addicts are actually self-medicating for psychological pain. Opioids been found to be efficacious in the treatment of depression and anxiety, but concerns over addiction prevent them from being marketed for these uses. I find this odd, because benzodiazepines are used for psychiatric purposes, but are also (less, admittedly) addictive, and their withdrawal symptoms are much worse.