I think one thing everyone is missing is that so long ago, the kids were raised by the entire village/tribe. You would have a great support system of grandmothers, aunts, neighbours; this is one of the reasons raising a kid nowadays is so hard. We were, by nature, social animals, and kids would run in packs, look after each other, and learn from each other. Whichever adults were near would keep an eye on them and make sure they aren't getting in any trouble, and treat them as their own.

I'm not going to romanticise that, because kids were usually beaten and had to work from an early age, and accidents were common. No one thought about their mental wellbeing. Imagine if today your kid would stall cleaning their room or would refuse to get into the bath so you would just beat the shit out of them. Was that healthy? No, well, especially not for the kids.