The issue with addiction is, it’s very often a symptom of other underlying issues. Relapse are common because too often the underlying problem isn’t treated. Overcoming the addiction is hard because it means facing the thing the addiction allows you to avoid.

Addiction is also common(ism) amongst those who suffer from NDP. In this case, is it truly addiction, or simply another tool in their NPD cache of weapons.

I don’t disagree with you. But it’s also important to be aware of some of the nuances and finer points. I also recommend reading “The Courage to be Disliked”. Not that it / Adler speak to addiction but it’s a thought provoking alternative to the Freudian paradigm.