Its probably been easy access since the 60s.Agree, poor choice of words. Public education, early intervention.....like with everything it requires a layered or network response and some people will fall through.
The people battling with it will have a life long battle regardless of the legality, they will always find a way to get it. I don't think we do keep the majority away from it in the long run. I went to 3 high schools, 1 in a low socio-economic area and 2 at the upper end. The kids who wanted to try weed at all 3 had more than enough access to experiment.
There has been easy access to weed for a lot longer than 20 years?
It tends to get left behind in high school for a lot of kids. And like I said before, you are restricted by the grow cycle to some degree. When it goes dry it gives people a chance to quit.
If its illegal a lot of people won't try due to the loser stigma. More open acceptance will change that.
You also get varying degrees of strength currently. Not the hydro potent strains day in day out if it were legal.
But then you have issues with pgrs and mould in badly cured buds( with the illegal stuff). So its a toss up.