Where did these things come from? Some list Korn or Linkin Park as the start of them. Others listing the rise of anime and weeb culture are the root of edginess. There are even those who say videogames and the rise of nerd culture.
But really it can be found to be in the Le Edgy Bible, JD Salinger's A Catcher in the Rye. Parents in the 50's correctly saw that this book would make their children into edgy, anti-establishment nihilists.
While they eventually failed in banning this book, the tried their best to keep the world as it was shown on Happy Days. Everyone knows that the 50's were a time of contentment and peace. Men were men, and women knew their place.
All of our modern problems can be attributed to le edgy losers.
What is the source of angst and edginess?