But there is more to being an adult than just intellect. And I question if it is even emotionally or mentally possible before puberty.
The point is that he is not talking to them about engineering, but sports, videogames or music.
Because people are different.
I started working at my first job at age 15 at a fast food restaurant.
I didn't get an allowance from my parents so earning my own money at a job felt really good. Working at that minimum-wage job was more important to me than hanging out with my high school friends. I was trying to save up for a guitar and hanging out with my buddies wasn't going to accomplish that. Also, being able to buy a new record from a band without pestering my mom for the money felt good too.
But I'm not recommending that other 15 or 14 year olds get jobs. I'm just saying that it's not some punishing psychological trauma for a high-school kid to work at a job if he really wants to do that. On a farm, the 10-year olds and 12-year olds running the tractor for the first time are doing far more arduous work than I did mopping floors and flipping burgers.
I don't know the subject of the story but if he really wants to work at SpaceX, that seems like a very reasonable path. There are already protective child-labor laws in California that regulate things like max hours a week. E.g. It already covers Hollywood children acting in movies and tv studios, etc.
The reality is that there's probably no good fit for this person, so it makes sense to leave it up to them and their parents decide how they want to spend their time