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, 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.
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.
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.
Furthermore, I think the author is losing a bit of historical context. For all of human history settlements have grown from a central point outwards. There has been a highly dense core, with decreasing density towards the suburbs. As time progresses the density spreads too to match demand and economic growth.
Only in the past century or so have large numbers of people been able to demand that this density spread stop or reverse itself, typically with the application of zoning regulations. This has put undue pressure on the cities where this happens between those trying to continue an ancient growth pattern, and those who are trying to stop it.
So from a very large historical view, those living on the outskirts of a city complaining about the spread of density are being unreasonable, because this is exactly what successful cities have done for all of human history.