the cultures that have lived longest have managed to conceptualise their life as a symbiosis with their biotic infrastructure, not a cancerous infinite-growth paradigm or some (related) fantasy of somehow transcending biotic reality, being "above" it or dominating it utterly.

That the latter can (and did, and does) dispatch the former without issue is part of the point I was making in writing this short essay. There is no shortage of answers to the question of how to live in balance on this planet, but for any of them to work, superior violence skills (that can be applied internally and externally) will have to be a permanent component of a "new way" in order to prevent being run over once again by challengers. Being able to balance those dual (and completely opposite) tasks takes a level of dedication and discipline on a planetary level that doesn't yet exist. Such a state of being may be possible, I just don't see it occurring before we're forced through a very chaotic period of contraction during which the current infinite growth paradigm also dies by (non-human) force.

we're sitting around talking about "inevitable doom" as if it were normal for human beings to create a culture that burns out in 250 years or less, when we have excellent records of cultures that persisted for 10,000 years or more.

I'm not sure what normal has to do with it - it succeeded because it defeated all other challengers. Whether such a way of being is the result of a social construction or biological dictate doesn't matter, because violence works. Again, here is my point stated another way: violence will ALWAYS score a win in the long run unless everyone agrees to not use it. There are ways to reduce violence, sure, but the concept of eliminating it seems as myth bound as one of the ideas I pumped with as a child - that sin can be eliminated by everyone giving their heart to jesus. To me, sin and violence are equivalent - they are chaos, and life (order) is a continual fight against the encroaching chaos. Chaos is the default state of the universe, not something you just throw out in the trash.

hell, even Rome took longer to fall than the US has existed as a nation-state.

We command far more energy than they did, rise and fall times can be greatly accelerated as a consequence.

you are the media you consume.