It's relatively light, very accurate, low recoil, and can be hightly customized, including the addition of an adjustable stock for smaller people.
Owners can be readily taught to make many repairs and parts are readily available. One could even buy a rifle kit and a stripped lower, allowing a youthful gun owner to build his or her own rifle. What a great parent-child project.
One of these days I'll learn how to install the bolt catch pin without scratching the receiver; not that I mind a small scratch. It's just the challenge of learning to do the job right. (I bought a "blem" kit but I didn't even bother to find the blemish.)
I agree with everything that you said. But for a youngster, for the first gun I would start with a .22 single shot, bolt action, or lever action. Not a semi-auto.
Following along those same lines, for hunting I would not suggest a semi-auto. Not for their first hunting rifle.
The parent-child building of an AR would be an excellent project. My son actually helped me build my first AR.