CoryThatWas, I think you are right, too.
There are so many factors and complexities at play.
I would guess that lots more of us would have an outright ban on drug use in the home, and that very few of us use drugs in front of our kids the way we drink, however moderately.
And yet very many of our kids will experiment with weed and MDMA, for example, and maybe use it recreationally a bit. All without parents setting a bad example or allowing it in the home, and almost 100% as a result of peer pressure / peer aspiration (i.e the peers don't pressurise them, they pressurise themselves to be seen to be cool or to just give it a try for the thrill / experiment)
Some of those kids will, sadly, develop a problem, progress to more problematic drugs or suffer the knock-on risks such as a caution or conviction. Having met many young and older people who have drug and drug-related problems I would say that the majority who succumb are those with problems - unhappiness and dysfunction at home, a need for self medication, a feeling that they have little to lose, trauma and events that have led to them not valuing (and therefore protecting) the quality of their lives. Obviously this is not always the case - some just get in too deep.
Our support for our children in terms of alcohol and drug use needs to go wider than just yes / no / what age can you have prosecco at Christmas. And still cannot be guaranteed to always work!