I'm sorry but that is such a privileged first-world take.

You haven't lived in overpopulated places.

I swear I'm starting to wonder if that's a take pushed by corporations so they can have an endless supply of labor and consumers, like the bans on abortion etc.

Energy is very easy to produce cleanly (nuclear, and solar is looking better and better). The barriers to doing so are political and financial, not technical. They will be made worse by having an aged-heavy population, which is less innovative, less willing to invest in the future, and less willing to try new things. And it makes a poorer society, obviously.

Malthus has been proved wrong at every juncture. Lack of children is about to bite us very, very hard.

This is like comparing apples to oranges to find a correlation, and arriving at an incorrect causation.

Falling populations are largely due to better education, specifically of women, as well as integration of women into the workforce, which has been one of the bigger drivers in curbing poverty. The latter is so significant in the west and the far east (double income households mean rising costs of living, meaning SAHM households become unviable in the West for the middle class), resulting in a significant population decrease.

But in places such as the Middle East or Africa, ever increasing populations have only meant even more financial trouble for those economies. Case in point Pakistan and Egypt. In other economies such as India (which I assume is one of the "couple countries" you mentioned), overall birth rates are falling significantly to near replacement level, and in the few states/regions with high birth rates, poverty is rampant and the people reliant on subsidies from other more prosperous regions.