> The surprising fact is that hunter-gatherer societies actually have substantially more free time than agricultural ones!

They don't actually have to. The reason why that is the case is because agricultural societies very quickly stratify - which happens because it is very profitable to be on the top in such society, since there's so much more surplus wealth produced by people under you that you can forcibly take away. Hunter-gatherer societies only see that at the richest end of their scale (again, the Salish were a good example of that), and even then the stratification is fairly meager by agriculturalist standards.

And so the farmers end up working more, because forcing them to work more means more surplus to take from them. But without that - i.e. if the farmer only has to feed themselves and their family - they do in fact have more leisure time than a hunter-gatherer would, simply because it takes less time to farm the same amount of calories.

> I also have to add that many of the advances we're talking about are not things that require any sort of special preconditions. I can setup a furnace capable of creating and forming steel in my backyard out of clay, straw, wood, and perhaps some leather if I really want to go all out and add a billows. Similarly I can even make gunpowder in my backyard - straw, wood/charcoal, sulfur, urine, and you're good to go!

If you already know how (and why) to make either, absolutely. But technological development itself is highly path-dependent. A person who is not familiar with the concept of smelting is not going to set up a furnace with billows out of the blue, because, well, why would they bother doing something as complicated as that with no good reason?

> For instance the Zulu were a warlike people, yet their traditional shield was made of cowhide! And it was "real" - not just ceremonial/ornamental. Obviously they were aware of the possibility of making one out of thin wood, which might be a bit heavier yet orders of magnitude more protective - yet they chose not to. Similarly they preferred to fight near naked, as opposed to wearing cowhides - which again, I think it goes without saying they were aware of the possibility of.

Yes, and many Polynesians similarly eschewed the bow for warfare despite knowing of them and even using them for sports.

But this seems to be an unstable arrangement that is easily upset. For example, Maori were also in the same boat wrt bows. But after Europeans came to New Zealand and Maori chiefs saw just how powerful guns are, a few decided that, whatever the custom is, they need to acquire some for themselves. And so they did, leading to https://en.wikipedia.org/wiki/Musket_Wars, in which many traditionalist iwi were nearly wiped out, and most of them also adopted firearms out of necessity. And note that this wasn't the case of Europeans pushing the guns onto the natives - no, Hongi Hika actually organized a mission to UK to see for himself how those warlike British people live, and to obtain the same arms (he exchanged the gifts received in UK for muskets and gunpowder in Australia on his way back).

And those who refuse to change - or change in the way that makes them intentionally less competitive in warfare - end up like the Moriori...

> Even simple things like fortifications seem to largely have not been a thing in much of the world in spite of never-ending wars. Simple wooden defenses, moats, etc are utterly trivial to construct, and that sets you almost immediately down the technological path towards the massive spiraling castles that would end up dotting the European landscape. But most of these other cultures simply failed to create such things.

Did they, though? Looking at Maori again, during their earlier, more peaceful period (when their population size was small enough that living off the land could easily sustain everyone with no need to fight for resources), they didn't have fortifications. But once that was no longer the case and their culture became dominated by war, their villages very quickly turned into fortified pā.