The tallest woman on Earth, Yao Defen, died because she didn't stop growing. The cause turned out to be a cancer in her pituitary gland
There are stages in the growth of all people. The first is physical growth to the early teens. During that period there is much learning of facts and a mental growth through what are called "concrete" stages of learnings. After that, the physical growth should stop, and be followed by a mental growth - that which psychologist Jan Piaget calls the "formal" thinking stage. As in Physical growth, there is a need for challenges and exercises in mental growth to achieve this formal level of thinking*. Without these challenges and experiences, even whole cultures will not "grow" to the formal stage, although their cultures may operate very well because the people are easily manipulated by privileged leaders who can think formally.
The same with of cities. Growth to maturity is good, but accepting unlimited population/area growth is ignorance or it is caused by the cancer of greed.
It is the rich and powerful Gordon Geckos of this world whose paid media pervade the media with the self-serving mantra that unlimited population growth of cities is good. That is because unlimited growth is what is making them rich and powerful of course. However, there are a few quiet intelligencia who are saying that it's time for the Governments of the country to get on top of the Geckos. Australia is far from a mature country. In Australia, Geckos reign supreme, due to the unthinking acquiescence of Parliament who are kept irrelevant by the unthinking acquiescence of a docile public.
On the other hand, there are countries and cities that reject physical growth, who are light year ahead of Australia because they have attained the stage of smart growth - Japan, South Korea, Singapore the Scandinavian countries and many more. They recognise the folly of growing population, instead they grow intellectually smarter.
Here in Australia we create special pedestals for "think tanks" but the government ignores them in favour of groups of compliant and overrated people who can rationalise the reasons for implementing developers' schemes. They are not think-tanks, they are merely another purchasable commodity.
To have a growth of population in a mainly desert country like Australia with no significant water supplies - rivers, is muddle-headed hara-kiri. We are well past the physical limits of our renewable resources. We now need a growth of wisdom and maturity and the kind of planning that goes with wisdom and maturity. The planning structures we have now are premised on a growth of population. Instead we need different structures to enable good planners to implement mature planning. Plopping surplus humans into tickey-tackey boxes on "surplus" green fields or brown fields or purple fields or pink fields is an insult to mature thinking and to the competent planners we have in Australia.
When we run out of energy.
Our Western way of living is dependent on using far more energy than is our share. But everybody demands the same quality of living which they reasonably equate with the amount of energy we use. It is the available energy that we have now that provides for the energy-dependent foods we squander. By 2060, fifty more years, this abundant energy will have been used up. The consequences of this is that we will be dependent on the food we grow ourselves within walking distance of where our one-room house is. Perhaps you might believe the people who constantly tell us that by then we will have found some new energy source. But consider this: in 1950 the wisest scientists predicted that fusion energy would cater for all future energy needs, and so squillions of dollars have been spent in the past 60 years trying to get it to work, without success. We are no nearer to achieving it than we were 60 years ago. That is probably because of the physical problems of containing and using the pressures and heat of fusion energy. Remember, it was less than a kilogram of hydrogen that produced the largest ever explosion.
A sad metaphor is the case of Yao Defen whose over-growth killed her. The cancer in Australia's case is developers who either can’t or won’t think formally. Why should they? Wealth and power is there for the taking, politicians and lawyers are easily bought, so the Gordon Geckos "logically" ask why not make a killing - literally. And it will surely kill or enslave us. If we continue along this path, the Geckos may soon be living in luxury in countries like ours that they own absolutely.
* Actually Piaget described two levels of formal thinking.