Those civilizations thought that it was the wrath of a god or two, or some war would consume everything. We have actual scientific evidence that our completely unhinged and largely unregulated use of resources that natural creatures have no access to is destroying our planet.
If the difference is hard to grasp then I’m starting to understand why the U.S. has undecided voters right now.
Anyone who would act like that couldn’t even hack it in a developing country today let alone going back in time. Remember, a dystopia is just a third-world country but with white people and that’s different because, uh, reasons.