All addictive habits are destructive to a greater or lesser degree.
There are at least four reasons for this down side to any addiction. The first reason addictive habits are destructive is that they are, by definition, habitual. This is not to suggest that all habits harm us. As a matter of fact, life would be more difficult than it already is without the habits that eliminate the need for constant decision-making. And so these folks typically miss out on a lot that life has to offer.