The line you draw between opioids and other drugs is a false one. Addiction will happen regardless the medium you choose to express that addictive tendency.
. . .
Same with heroin, or any other narcotic. It's a choice.
Except different substances react with the body differently and opioid use literally reprograms your brain. So once you start going down that rabbit hole, it's pretty easy to get lost.
According to position papers on the treatment of opioid dependence published by the United Nations Office on Drugs and Crime and the World Health Organization, care providers should not treat opioid use disorder as the result of a weak character or will. Additionally, detoxification alone does not constitute adequate treatment.
Edit: The Wikipedia article has a video that's very informative in very plain English. It's very much worth a watch.