You seemingly state that as a positive goal. I posit that many people would have preferred to be left alone and not killed or subjugated. Perhaps if he had been prevented from those actions until after maturity, he would have chosen different actions.
To rephrase the other user's [correct] sentiment, a scientific determination of brain development has more to do with myelin on axons than maturity regarding emotions, finances, or anything else we actually judge people on.
I had a job at 13 and would've spent my own money on something like this.
We treat adults like children so children behave like infants.