“It’s been the way people have been growing up for millennia all around the world.”

I don’t think this is a very convincing argument. There are many, many things that have been around for millennia that just aren’t that great. We’ve been living without vaccines, antibiotics, antiseptics, antihelminthics, poor nutrition, extremely high rates of childhood mortality, and high rates of death by childbirth for millennia. That doesn’t mean that state of being or way of doing things is inherently good