A lot of people who are against drug use want them to be illegal and dangerous to use. Someone overdosing from buying drugs illegally is a preferable outcome for them because they think it will discourage people from buying illegal drugs.
They want the drugs to be both illegal and dangerous.
In reality making them legal and regulated decreases use and is safer for those that do, which doesn't work for people who think suffering is the goal.
Plenty of street drugs are addictive and dangerous even in their pure form. See for example the opiate crisis where many people started their addiction with pharmacologically pure prescription opiates.
While true, a large majority of the overdoses in the last decade are due to street drugs not being pure. The clean drugs will kill you eventually, the street drugs will kill you today.
The clean drugs will kill you eventually, the street drugs will kill you today.
The most common way people die of heroin/opiate overdose happens when they have reduced/stopped their consumption for a while and then something happens in their lives that makes them go back to it. On the first time they use it again, they overdose because they have lost some of their tolerance.
This very common path to overdose will happen whether the drug was pure or not. The root cause is that there is fairly narrow band of dosage in which you get high but don't stop breathing altogether.
Providing pharma grade hard drugs isn't the panacea that some people believe. Nuance is necessary. I haven't even touched on the very real downsides of living next to a clinic that provides services for people addicted to drugs.
I live next to one such clinic in a huge city. It sure beats having neighbours OD in your backyard or shoot up on the sidewalk. There was a small vocal minority worried about their law and order who tried to shut down the site, and hundreds of neighbours showed up to tell them to pound sand.
Safe supply is healthcare. The people accessing safe supply and safe injection sites are much more likely to be getting help.