There's no need to wait, just look at the current mental health crisis.
He didn't. You're the one that brought "solely" into the conversation.
"Teens are sad because they spend all their time on their phones", then maybe ask yourselves why teens flee to their virtual spaces. (maybe look at what seems important to them and is at the same time being dismissed and ignored by the people older than them, while being told not to be idealistic and naive.)