Would you let a 4 year old live alone or would you call that abuse? At 16 we might survive, but are more likely to flourish and less likely to die when under the care of a guardian. At 16, we want independence, but make bad choices. We can not help it. A guardian can structure increasing independence by first assigning life-tasks under supervision: check the adolescent’s study habits and school work, allow the teen to cook, clean, shop, and budget – but be there to help and advise if/when needed.
There are cases where the parent or guardian is so selfish, awful, or abusive that a teen is better off without the damage caused by their home situation, but in general, these are dangerous years to be unsupervised and countless studies prove it.
The point about a 4 year old is a rhetorical device. No answer is expected. I constructed it to illustrate on the biological reality that you are not grown at 4, just as you are not grown at 16.
We agree that helicopter parents are bad, and we agree that parents should prepare their offspring for life, then let them fly free. Our only disagreement is on how much freedom should occur at what age. I ask you to do some research and cite some sources before opining as if your random thoughts should get the same weight as documentation from people who devoted years of study to the subject.