It's top down and intentional.
Singapore promoted feminism to intentionally reduce their birthrate in the 1980's. Bill Gates is just one of many promoting depopulation actively. Yuval Harari and Klaus Schwab are promoting depopulation through sedation (computer games and drugs).
Even MIT produced one of the "Earth is unsustainable and collapse is imminent" types of propaganda films back in the 1970's (
link). The film explicitly states at the end that they need to convince not just the lower classes not to reproduce but to control the birth rates of everyone, saying disease, war, and famine are good for pruning a population. They say that if we don't stop reproducing then we'll run out of copper, zinc, silver, iron, and other materials by 1997. Scary music and all.
Of course, a prize should go to anyone here who can find an article, film, or book that speaks about overpopulation with someone other than Europeans in mind. I've never seen one. Africa and the Middle East have enjoyed a very high birth rate thanks to Western foreign aid for 60 years now.
I think too many people look at this from the bottom-up instead of top-down perspective. How about we just admit that the people in charge of us have goals that harm us and know what they're doing instead of just continuously excusing them as "incompetent" and "stupid." If Gates is travelling the West talking about eg. eliminating meat from our diets and then he buys a bunch of farmland, then I'm going to assume the man has a goal and it's taking effect. Especially when multiple diary, beef, and chicken farms start running out of business within a 5 year span all of a sudden from out of nowhere.