To have a physical addiction to alcohol or opiates one needs long term use. The body needs to habituate to the substance. And the body has withdrawal symptoms.
Alcohol is the dangerous withdrawal.
Opiates, no so much at all.
I’ve heard that opiate withdrawal is bad. I have heard that methadone withdrawal is downright awful, but I have no direct knowledge of any of that.
I do know that withdrawal from benzodiazepines is Hell.