Yes, we do move on and refine our definitions and understandings. Obese was once merely grossly overweight, but now the accepted definition is "an excess of body fat that frequently results in a significant impairment of health." I think the new definition makes more sense from the standpoint of health. I also think that the new awareness and improved definition of addiction is much more accurate and in tune with reality. After all, by definition, anything that is addicting can become therefore become an addiction.
Insofar as no one needing to compare heroin addicition to addiction to video games, I do not see anyone here saying that the two should be compared, though both can become addictions - the same as I would not compare a motorcycle to a transit bus, though both are motorized forms of transportations. As far as chemical changes and dopamine receptors a great many things can bring about such changes if they bring pleasure, including bubble baths and back rubs. Or listening to music. Or playing video games and there have been studies that prove it (look it up!). Addiction is a subject I know well, having studied it and having worked with addicts.
I am glad to see that you recognize that there are varying degrees in things like addiction and chemicals. You seemed to indicate just the opposite when it came to supplements and drugs when you said regulation is regulation.