"Adolescence is the onset of adulthood before the capacity to function as a real adult in the real world is reached."

In the past, adolescence was the onset of adulthood, period. In many parts of the world that's probably still true. It's our modern society that keeps young adults trapped in childhood until they're 18-21+.

That aside, I think it's the parent's responsibility to make sure their kids develop the capacity to function as adults by the time they have to start dealing with this stuff. Unfortunately that often doesn't happen, which leads to the problems you describe.

Maybe what we need to be doing is teaching the parents how to teach their children to be adults, through a medium that reaches both the parents and the children. We need "How to be an Adult" video games on mobile phones, perhaps.