Same for alcohol. Restrictions on who can buy, who can sell, and how you can advertise and market.
These are not the same as some random pill from a gas station sold to anyone with cash with zero regulations, safety, restrictions, or even any requirement to tell you what's actually in it.
I remember traveling to mexico and being surprised.
Giant "Marlboro Man" billboards.
Television advertisements for hard alcohol.
but what was also funny was Coca-Cola ads always had something like "Siempre come frutas y verduras" (Always eat fruits and vegetables)
(nowadays mexican food labeling is even more specific, saying stuff like "excess calories" or "excess sugars" https://en.wikipedia.org/wiki/Food_labeling_in_Mexico )
I am not that old.
Better regulation, better enforcement, anti-smoking advertising campaigns, banning public smoking, and drastically reduced amongst youth and the general public.
Cigarette regulation to reduce smoking starting in the mid/late 90s is the poster child for public policy done well.
The regulations on selling tobacco in person AFAIK are only for cigarette and cigeratte labeled type rolling tobacco. You can still order perfectly cigarette smokable "pipe" tobacco online straight from an internet "vending machine" and probably a real one. Very few people know this though because it turns out to not actually be a much of a problem.
In practice I think most young people who want to drink will just get it from a "cool older brother" or steal it, whether from parents or corner stores. At least that is what I saw in semi-rural America.
People will do what they want to do, with or without vending machines and online ordering.