It's not an appeal to an idyllic past. It's the recognition that human development seems to follow a pretty consistent pattern, and that fighting it is going to take a lot of energy and have unintended consequences.

If you notice that a certain part of a mountain near you has consistent avalanches, then you really shouldn't be surprised if a home built near it gets knocked flat on a regular basis. You can build a giant wall next to it, but at a certain point you should recognize that you ought to build elsewhere.

Similarly, if you want to live a low density lifestyle, don't build close to a thriving metropolis. The only time they don't spread is if they start to fail, or if there is some natural barrier stopping growth.

For most of human history there has not been such a great incentive to live in or near a large city. Because there is such an incentive, you now see people struggling to build enclaves they like living in that are reasonably close to work, rather than going to live in the Great Plains. I don't really see that much about human development is "natural;" humans control the process and are free to make decisions about it.

That’s not true at all.

For most of human history, cities did not actually reproduce enough to maintain their own population. It’s only into the 19th century when cities start to become self sustaining.

If there wasn’t pressure to move to the city then they would’ve collapsed millenia ago. It’s not like there’s this permanent cohort of city weirdos living in the great urban areas, those areas continue to draw in people from the surrounding area.

The modern economy has a much bigger role for cities, and the percentage of the population living in cities or metro areas is historically high. So in fact I do think it is true.

Yes, urbanization is very high right now, although most people underestimate the degree of urbanization in ancient civilizations.

This has less to do with a change in cities than it has to do with the precipitous drop in demand for rural labor of all sorts, imho.

I'm not sure how you tease those two out, as they're kind of mutually reinforcing.

That’s the nature of dynamic systems. You probably cannot tease those apart.

The overall point is that there has always been a drive to push people into cities (otherwise they’d collapse due to mortality rates). The overall rate of urbanism and urban change has fluctuated over the millenia, but it’s hardly new in any meaningful way.

Hence my assertion that anyone living close to a growing metropolis should not be surprised if the density overtakes them.

They might not like it, that’s perfectly reasonable. But expecting things to not change in your area only is actually quite unreasonable in the long run.