I think there's a fundamental type of human who walks among us who doesn't have a sense of self - but you're right that teenagers quite often grab random styles and ideologies to try on, a little like a coat. They join a subculture and they wear it for a bit and then they let it go. Back when i was a hatchling, goth was a very good example of this, now it seems to be cosplay, which does much the same thing but has been far more sexualised. My issue isn't with that; rather the mechanisms by which these ideologies hold people - people can put them on, but the cost of taking them off is high. Social media has created communities that are highly bonded, escalating in nature and full of interpersonal toxicity. And so you have people in their late twenties, thirties and forties who have given away their personal identity and a quest for individuality in favour of becoming a mouthpiece for X.

And yes, without deliberate effort and thought I think you become a non-entity. Non-entities are dangerous, they look like people, they walk like people, but they aren't people - they don't have personhood in the way i think about it- they are how you end up with an SS division moving around killing, raping and existing without question. Empty vessels ready to be programmed by those around them. People should be working on their individuality with one eye on the toxic hold of ideologues in the way they differ from K-Pop or that boyfriend. :o)