And nothing heinous has ever been done without religion?
The faithful give over three times as much in charitable donations as the secular, and volunteer three to four times as often.
Plus, the religious have been persecuted for their beliefs as long as there had been human history, which is what you are proposing by suggesting that religion should be eliminated.
Maybe it depends on where you live. Currently, our local politics is poorly attended. I shudder to think of the average local teen making community decisions. Among other things, we would end up with no police and my community is already stained for police presence (though some would consider that an advantage, I live too close to a high school to be comfy with that.) I’m guessing in more affluent areas, that might not be a big of a risk, but it definitely is here. Most teens here don’t traditionally work anyways.
Voting within their school, sure. But not at the community level.
Besides all the reasons other commenters have said, it’s because mental health is a pseudo-social phenomenon among teens.
Having a mental illness gets them attention, online and in person. I have two teens, and even though both have diagnosed mental illness due to trauma from their other parent, they still seek, discuss, and revel in self-diagnoses.
If a friend claims to have something, they rush to the internet to do “research,” and begin exhibiting “symptoms.” Same thing is true with other labels.
We have a dearth of parenting, due to needing two incomes to make a household run. Adult attention is scarce, so teens make up for it with wild claims and garnering attention from other teens. The internet makes it easy to model behaviors. So yes, there is an increase in mental illness, but not the kinds, nor for the reasons the internet would have us believe.