India for example, a country with lots of poverty that is already struggling to feed its population after just a little bit of fuel price jumping, has no business being at what, 1.4 billion? Why should we continue to grow even further beyond the limits of a country?

India is already below replacement rate.

Well, there is, if you don’t use a binary indicator of above/below replacement rate, and don’t just take “south” as geographically south, but rather as “poor, exploited countries, usually (but not always and exclusively) in the south”.

You're missing the point. This isn't about geography. This is about the actual countries that get labeled as the global south. That includes India, China, Southeast Asia, South America, etc. These are the countries that experienced the worst of colonialism. And they're all heading straight towards population decline, just like the global north.