Many of my school colleagues started smoking around 10-11 years old. All of us had tasted alchol by then, and some of them were definitely drinking the occasional beer. Older kids sometimes brought porn magazines in school and would show younger kids too (still talking about pre-highscool here). Now, this was childhood in Romania in the 1990s and early 2000s, soon after the fall of communsim, so maybe not so applicable everywhere else, but still - I doubt that there is any problem for a resourceful 8-10 year old even today to get some of these things.

There’s a difference between “saw a playboy once” and having regular or semi regular access to it.

Same goes for alcohol and cigarettes.

In the US, If you had regular access to those things, you had parents who didn’t care.

It’s also not about kids on the margin. The vast majority of 8 year olds in the US have not tried alcohol, drugs, or cigarettes.

I can’t rely speak to post Cold War Romania.