Ok, there's been more education on STDs and teen pregnancy, but even still, because of WhatsApp/Facebook messenger, a lot of what used to happen in the hallways (or at least how Hollywood depicts it) can how be "virtually" hidden.
Less than being worried about the 'why', I'm just stating the facts. These studies usually collect information via anonymous surveys, and generally there's reason to believe that these surveys are reliable.
Saying "it just happens virtually now" doesn't change the results of the studies. We aren't measuring by listening to hallway conversations, we are measuring by directly asking teens "are you sexually active?", in a safe, anonymous environment.
I totally agree, for whatever reason it's decreasing. The reason I mention hallway conversations is that that's the way OP or any non-statistician would perceive these things. That's why he says
> nobody's f*ing or even dating at all.
while your link claims
> In 2015, 41% of high school students reported having sexual intercourse.
