Early humans (as well as feral ones), still have intellect. It is the human ability to analyze and use strategy to overcome the lack of physical adaptation that led to us being dangerous even before using that thinking to develop weapons. Most animals are physically better adapted to the environment and for specific tasks like hunting, but none of them are "far smarter". Neanderthals were arguably about as intelligent, and we don't really know what happened there, but most of the evidence points to a sheer numbers game because we outbred them. Zombies are humans without that problem solving intellect, sure they lack empathy or any value for life, but that just means they won't hesitate to slowly lurch mindlessly forward for them tasty braaaaaains, its not going to make them better at avoiding traps, sniper rifles, drones, being herded into a killzone, etc.
Both the human history of expansion and the human history of warfare suggest intellect isn't actually our strong suit. We did not settle the Midwest of the U.S. by simply adapting; we settled it by throwing people at it until enough of them survived for permanent settlements to be maintained. We did the same thing with the early American colonies, the Australian settlement period, and so on. We explored using a very similar method, the throwing of bodies at it until we accomplished our goal, for much of human history; both Antarctica, Mt. Everest, the Arctic, the Sahara, North America, South America, and so on were conquered via this method.
I've seen both human warfare and human exploration described as "apply face to enemy," with a note that applying
enough faces is far more effective than any clever strategy that can be devised. I think it's an exceedingly accurate description of our species; we simply stubborn nature into submission.
We're also not the only species with tool use, even creative tool use for solving complex problems; a number of primates, corvids, and other animals have been shown to utilize tools and problem solving on a level that can only, under our science, be considered human. And these are very likely not recent developments.
There's also growing evidence that we may overestimate the intelligence of both our species and Neanderthals during that period of time; a number of species around the world have shown growing intellect as a result of surviving in human cities, leading to the very real possibility it is not our intellect that caused our tool usage but our tool usage that caused our intellect. That, in effect, our entire idea of how human intelligence evolved was backwards. But, then, this wouldn't be the first area of primate evolution we had backwards.
Zombies may have been originally used to depict the horror of humans without civilization, but they had to change to being about the dehumanization of consumerism because we saw too many examples showing humanity's true horror potential isn't restricted by "civilized thought" it is amplified by it. A species without the ability to contemplate power dynamics and rationalize actions might hunt another species into extinction but they aren't going to delay their enemies' extinction in order to torture or oppress them which is what civilized humans have done countless times throughout real life history. To make matters worse, when a society of humans commits atrocities we don't get to blame it on them being inhuman, zombies are literally us lying to ourselves to think that civilization is a panacea to the evils humans are capable of.
Cats and dolphins both practice the delayed death for torture purposes and domination aspect. There's growing evidence that practice may also be standard for many primates closely related to humans; if anything, we may be the
least cruel of the primates in that grouping once you look at what chimpanzees do to each other (most humans would not kill and consume someone else's child right in front of them simply to show dominance, for example).
And I could go on. There are literally millions of examples in nature that show humanity's capacity for cruelty is not only not unique, but not even exceptional. That's part of why some people are considering the possibility Earth might actually be a real-world example of a Death World; in essence, the idea that among inhabited planets we may be living on Space Australia.
But, yes, I did state the traditional idea behind zombies been watered down to it being us lying to ourselves
To be clear I love a good zombie movie, I'm not antizombie. Its just that zombies are less horrifying than people could ever be which is why they are pretty much just set dressing and plot convenience in the walking dead where the real antagonists are almost always other humans.
Who are still comparatively nice people. Even in the modern age, humans do far worse to each other than is depicted as humans doing to each other in zombie movies. So it still carries the lie that we are not as evil as we actually are by saying we only get as bad as depicted in those movies when there's an actual apocalypse going on. If anything, the zombie movie portrayal of how badly humans treat each other is probably the most optimistic possibility.
