I don't think it is irrelevant. The point is about how to help someone. Trying to get someone with a physiological addiction to realise the error of their ways is futile, like telling someone to unbreak their leg.
It might tell you that it is quantitively different, but not necessarily that it's qualitatively different.
> Trying to get someone with a physiological addiction to realise the error of their ways is futile, like telling someone to unbreak their leg.
I think your understanding of addiction is probably lacking here. Many people can and do overcome physiological addictions due to some or other realisation. Conversely many people cannot overcome addictions without a physiological component, like gambling, regardless of how much they realise the error of their ways.
Whether it's physiologically addictive or 'merely' psychologically addictive is somewhat irrelevant - are you going to belittle gambling addiction as just a "bad habit"?