" You could travel freely pretty much anywhere, no roads required." Nope, only in steppe-like environments, where horses are native. If anything, technical ci

" You could travel freely pretty much anywhere, no roads required." Nope, only in steppe-like environments, where horses are native. If anything, technical civilization tends to de-fragment environments worldwide. You can drive the same car in Patagonia or Borneo as long as the road is there, and your phone will use the same stack of communication protocols. Of course, it has externalities. The question is how these externalities can be mitigated. But a humanity numbering 8 billion people can't realistically think of individual self-sufficiency at a scale, and not even tribes of hunters and gatherers, 1000x less numerous, were ever composed of self-sufficient individuals. We might be more fragile than our ancestors, but we also gained some other forms of resiliency that they didn't have. Humanity actually passed through a bottleneck event about 70 thousand years ago. https://en.wikipedia.org/wiki/Toba_catastrophe_theory#:~:text=Genetic%20bottleneck%20hypothesis-,Genetic%20bottleneck%20in%20humans,eruption%20on%20the%20global%20climate https://en.wikipedia.org/wiki/Toba_catastrophe_theory#:~:tex.... It would be a lot harder for a single natural disaster to threaten survival of the entire Homo sapiens species today.