You make a persuasive case, but nicotine is genuinely addictive. Something to do with releasing stored glucose and substituting for food, and causing irritability on what I take to be a physiological level on withdrawal. Otherwise I'd agree.

But in this context, is it so important to distinguish between whether something is physiologically addictive vs. just seriously habit-forming? Except for substances where withdrawal is genuinely life-threatening, the practical difference seems to be in degree, not kind. Nicotine withdrawal causes irritability, but (I know having experienced both) so can breaking a bad social media habit.

(And it seems like there's a physiological basis to both cases, it's just that one involves endogenous chemicals and the other doesn't)

That system has massive holes. Using convenience store employees many recent immigrants to be the gatekeeper to cigarettes for your kids seems foolish. Who trusts that last line of defense? If a kid fails at once location another location will succeed and there are no punishment for attempting to purchase underage.