I can think of many, many times when I was under 12 that I did things on my own. I remember walking to the shops that was at least half a km away well before the age of 12 by myself and sometimes taking younger family members along with me.
There are many cases now where young adults are having difficulty at tertiary studies or their first real jobs because they have been so protected and haven't developed resilience. We need to focus on what young people can do!
BUT For some reason though the car one doesn't sit right with me. I always worry about little kids playing with the handbrake and stuff & actually having the car running is a concern in terms of "inviting" potential car thieves.