Young people learn way more efficiently because their brains are still developing. Our adult versions are still on whatever trajectory was set by our younger selves. If a child is passionate about this subject matter, by the time they're 15, they'll probably be extremely good at it. By the time they're 25, they'll be better than any adult who started as an adult.

Today's 15-year-olds live in an entirely different world. The opportunities to find interest in this subject are vast now. That wasn't the case 25 years ago.

I would put money on a 15 year old establishing AGI before you do it.