

Is your life harder to manage because too much coffee? yes = addiction; no = acceptable
Is your life harder to manage because not enough coffee? yes = addiction; no = acceptable
I don’t disagree with you. I’m just hoping to point out the flaw in that logic. Effect on life management is one aspect of one type of addiction in my opinion. There is more than one type: mental (pathologically doing something known to be unhealthy i.e. smoking) and physical (negative physical symptoms after ceasing something routine i.e. opiate withdrawals) come to mind. I could argue there are also social and antisocial addictions (i.e. gambling and masturbation) which can still be done without immediately making ones life harder to manage, but they might and eventually will, most likely, but not necessarily.
Addiction can be nuanced. I feel it’s important to not set a bar like that, as an addict will use that to excuse or enable or deny that their unhealthy behaviour effects their life, sometimes without even realizing it.
People can smoke cigarettes without interfering with higher priorities. I don’t feel it applies to ‘most addictions’. It applies to a lot of them, but the opposite can be true sometimes too. I’ve known alcoholics who would have to call off work if they STOPPED drinking for a day, who would not be able to visit with family/friends unless they had a drink or three first.
It’s a good rule, I agree with that, but not necessarily for most addictions, especially the more entrenched one has become in the habit.