I read about this concept in a book about Ecofascism. The problem with that Malthusian way of thinking is this: Who will we leave behind? How are we gonna implement eugenics? Capitalists are a clear minority, and most of the global south seems to be an excellent target for answering that question.

A better way to look at the problem is to de-escalate and simplify. I mean, if you care about your fellow human beings.

Most of our work is already bullshit, and our industrial capacity (for the most part) can give us nice stuff. At the same time, we get rid of the high-polluting options. The world's population would self-regulate in horizontal societies just because everything has been that way historically. The phenomenon of hyper-poblation is a centralized-power thing.