People who quit smoking are actually quitting a synergistic cocktail of drugs - nicotine and a variety of MAO inhibitors found in tobacco smoke. There is good evidence to suggest that these MAOI components dramatically increase the addictiveness of nicotine.

I'm not really sure whether I can or should dispute your basic point, but I will say that pharmaceutically pure nicotine is radically different to tobacco smoke.

https://www.sciencedirect.com/science/article/abs/pii/S01618...