They just mean it in the way that we can become addicted to anything. You can become addicted to sugar, working out, a bad relationship, etc. it’s one of those “technically you’re right” things but by that point it’s just someone’s addictive personality and mental health. Most of my stoner friends, myself included, have gone long stretches where we smoke whenever we can but somehow have none of those withdrawal symptoms when taking a break for a couple of months so we can pass a drug test for a job. During the break we may feel like “man it would be pretty awesome if I could smoke with you guys” but we aren’t needing methodone or something to ween off of it.