my son, 16, is like this. Emotionally he is still quite young, even though he seems oddly old/cynical in casual conversation because he is obssessed with (bad) news and, more broadly, has a sponge like knowledge of facts (but not an ability to put them to good use!).
He has only one friend, because he struggles socially. he used to do pretty well at school but now has gotten terrible grades, mostly through not turning things in, and doesn't seem to care. the teenage part comes out when we try to help him get more organize--his homework, his disgustingly messy/dirty room, etc.
He still likes things that young kids like, even eats like a 12 year old, hates getting his hair cut, dresses in sponge bob crocs and stuff. Definitely does not help his social life.
I think part of it is real distress about the world he is growing up into==with AI, politics, economy, he feels very much like he will never have a good job, relationship, buy a house, etc. And part of it is his emotional/LD profile--a smart kid who is socially rejected, and does poorly and his self esteem is kind of in the toilet.
We've also failed to find any psychologist who helps him. He doesn't believe in it. doesn't open up and basically uses the time to tell them what he thinks they want to hear. After years of therapy, and then stopping, we have seen no difference in his emotional regulation.
Does not help that younger sibling gets straight A+s and has amazing executive function, friends, etc.