Because it is the ad network that I chose 30 years ago that was doing any of the types of tracking you mention. In fact, all of the ad networks from 30 years ago would be considered as doing "teen tracking" today. I do not know how you can do tracking without doing teen tracking, barring precisely I troducing age verification on every single website. And I also do not know if there is any network out there doing advertisements without tracking -- certainly none of the major local news websites use it.

I do think the "wont somebody think of the children" arguments are in bad faith though, and I say this as a father.