The education-industrial complex is structured around organizing children by age. This is a bad idea for so many reasons.
First, it is based on a false assumption - that young people of the same age have roughly the same skill level in subjects across the curriculum. Clearly, this is not the case. Even the maturity level between genders is a schism. And of course different students with different interest have wildly different abilities. But it remains an “objective” easy criterion, one whose inaccuracy has done nothing to minimize its use.
More importantly, putting children in groups of “peers,” organizing students to emphasize their social sameness, necessarily forces them to emphasize and exaggerate their differences. (Imagine the Kafka-esque nightmare of being part of a community that was organized because someone thought you all were inter-changeable. You would spend a lot of energy differentiating yourself through your actions, your dress, and ultimately through forming social cliques.)
Monocultures don’t work. They are the product of a dated manufacturing mentality of mass production, and seldom found in nature. That is why the waste from a deer in the wild enriches the soil, while sewage from a massive pig farm causes a health risk to the communities that live downstream.
In childhood learning, diversity of ages and experiences allows everyone to find their strengths in a vibrant ecosystem. Adults and kids should interact. Older people can mentor younger. Younger can use their strength and vitality. Each, wanting to contribute, find their role.