This is a logical fallacy that has been bounced around, in catastrophic terms, for centuries. (see Thomas Malthus [1], "The Population Bomb" by Ehrlich [2], etc.) Ehrlich went as far to say that in the 1970s, HUNDREDS of millions of people would starve. Did that happen? No. These ideas about some theoretical limit on food or resources of the Earth are alarmist and do not benefit the public discourse.
Sure, maybe the Earth has a limit to how much population it can support, but it could easily be 100 billion. Who knows? Do you know that the entire population of the Earth can fit in an area the size of the state of Texas, in single family homes? [3]
In contrast to the disproven "unsustainable growing population" idea, depopulation and the aging of the population will have severe consequences within the next few decades, and already has had negative consequences in places like Japan [4], Italy [5], and many others.
We definitely need to deploy policies to increase the number of births to address these issues.
[1] https://www.britannica.com/biography/Thomas-Malthus [2] https://en.wikipedia.org/wiki/The_Population_Bomb [3] https://theblogmocracy.com/can-you-fit-the-entire-world-popu... [4] https://www.bloomberg.com/graphics/2019-japan-economy-aging-... [5] https://www.bloomberg.com/news/articles/2020-02-12/italy-is-...