The article makes some good points but I think a lot of it is cyclical. Drinking, the very first activity mentioned in the article, was hardly considered weird or deviant for many of us growing up. I'm sure there are cultural factors at play here (I grew up in Ireland) but when I was a teenager it was the non-drinkers who were weird. Drinking was what our parents had done and their parents before them. Some of the more benign illegal drugs like weed were not so common that it was weird not to do them, but they were arguably common enough that they lost their weird status.

The decline in teen pregnancies can probably be explained (in part at least) by better access to abortion and contraceptives.

And as for the internet becoming more homogenous, this is a super very complaint on HN but I have long doubted it. I already know there are parts of the modern internet that are weird as fuck to me (just yesterday I read an article posted here about "gooning culture"). Objectively, the internet is just so much bigger now than it was then that it is statistically implausible that there isn't more weird stuff on it. HNers (myself included) are just in a relatively normal bubble.

But certainly the fact that we are all constantly online now can only encourage homogeneity in thought and behaviour.