This might be controversial but three out of four listed reasons where always there. The only thing that's changed in past 10-20 years is access to social media. Years ago, when I was a teenager, we had academic pressure, family dynamics and global events. And somehow majority of us got though it. Nowadays, social media creates a crooked image of how life should look like and it puts pressure on young minds.
But there's one thing missing from the blog post - helicopter parenting. Kids live in a bubble created by their parents. When being exposed to a real world, young people are not equipped with needed skills to survive the outside world.