It doesn't take much to put together the pieces. With increasing affluence, parents were given a greater opportunity to protect their children from the realities of life. It is clear that children are not always capable of facing real life challenges. However, the age for just when they are ready for many of them, seemed to gradually shift further and further. (Something that was no doubt encouraged by the longer periods of time required to complete the education for many vocations.)
Until we arrive at the present day. Teenagers are more or less assumed to be parasites on society, incapable of true contribution to it. Until, that is, they are magically transformed at the arbitrarily chosen 18 year mark into full fledged members of society.
I would argue that all this impacts how we teach kids in schools today. Instead of introducing them to truely independently useful skills, there is an uspoken rule that they aren't actually capable of anything useful just yet. Instead we play pretend, teach them some ideas that might one day lead to something useful, and expect they'll be satisfied with the experience. Highschools often cram kids' heads full of mundane method after mundane method, with little explanation as to how they work or why they are relevant. There is a litany of seemingly random factoids to be memorised. Abstract thinking is a lofty skill reserved for the adults and we needn't waste our time trying to evoke anything of the sort with these kids.
So yes, in a way I think our expectations of what our kids are capable of, do need to change. Not only on a superficial level where we just get them to work harder within the existing broken system. But a new approach is required where their full potential can be challenged.
It's easy to make such grandiose sweeping statements of course, but I maintain one of the keys is not stopping short with purely theoretical methods but extending them to practical realities. Yes, that is more challenging. Let's stop assuming that the challenge is out of grasp for these young people.