I think I would have been one of these people if I hadn't also suffered from depression and extreme social anxiety at that age.
In my late 20s after a bit of therapy I self diagnosed with narcissistic personality disorder. The therapist didn't dissuade me. It messed my head for many years after.
When you are an outsider as a teen who can't form proper friendships at school, university is like a utopia. All those years hiding in your room hating, hating, understanding nothing but believing you are the one who knows the truth. Obsessed completely with your self and your thoughts and your hatred of your own body because society has rejected you.
Then university. You find your tribe. It is a kind of euphoria to be accepted at last. A fresh start. Your desperation to be accepted by these people is extreme. I spent hours online chatting with these people. Hardly left my room. Didn't bother with study. Almost failed. Having friends and my own inner thoughts was everything. A true bubble.
I was highly vulnerable to conspiracy theories at that time. Luckily it was too early, before the worst ones came. But I was a 911 was an inside job believer and revelled in my own cleverness.
I guess things changed when I got a job and met normal grown adults and mixed more widely.
The NPD thing though... I still struggle with a deep urge inside me to hate everyone and everything. I am a victim who is somehow superior to everyone else. I struggle to keep friends, these days from keeping people away on purpose so I don't find opportunities to abuse them, but also people just know, I suspect, that I am not a nice person deep down.
I have spent a lot of time working on my empathy and critical thinking skills such that I believe I am now able, with enough time to filter out my gut instinct to dismiss and hate and ridicule, to turn my thoughts into something much more sympathetic, believing in other humans capabilities, respecting their freedoms. It is not instinctual and I do slip up but I have built good processes to get myself there eventually.
I think I understand these kids very well, and I am not very hopeful for them. They might figure it out as they go into the real world and realise they are a very very small minority to think this way. Then they just moce on with life (harder when you live in a bit city the bubble continues longer).
I think the Intervention forces needs to start young as pp said, forget the teens a d students. You cannot resolve this. NPD cannot really be cured. It is rare to understand you have it, because it is catastrophic to your psyche, and it was to mine. But pull through that and you can find a cure, I believe I have. Noone else will do it for you. They are lost, best ignored / the law applied to their actions. Focus on the little ones now, stop this from happening to another generation of outsiders. We need a way to focus the attention of the freaks and geeks and their hyper focused adhd type brains to avoid them heading to dark and toxic places.