Well, I've had lengthy debates with antinatalists on my old blog and on YouTube, and that debate is comparable to the question of eugenics.
But let's cut to the chase. The question you're raising is whether there's a conspiracy afoot to lower the human population by killing off large numbers of people one way or another, to save the species and especially the insiders. There is indeed a problem of overpopulation, and those who say we have nothing to fear from it and should keep up our population growth forever are likely beholden to faith in some religious fundamentalist creed or in technological progress.
The problem with accepting this kind of conspiracy is that you have to weigh the evidence against the possibility of sheer incompetence. Conspiracies require central planning, but that kind of planning is rarer than we might think. Even when leaders plan, they come up against the fog of war and against the unintended consequences of chaos in the environment.
I suspect many secular progressives and environmentalists think they're being moral by not having children, because they don't want to add to our overpopulation. However, by perpetuating their consumer culture, they externalize the costs and transfer the damage to the Third World which is the source of the booming population growth. Rich countries tend to have lower birth rates than poor ones. The best way to curb population growth would be to enrich the poor countries. That's what's happening in China. As the middle class rises, the majority no longer want to have a dozen children per family, because of their new living standard and lifestyle.
I'm actually writing an article currently that addresses the arrogance of elite intellectuals, which casts doubt on the logic of the full Covid lockdown. Whatever the unintended effects of mask-wearing, I think the medical reasoning behind them is plain enough and outweighs that particular conspiracy theory. But I never said I "hate" mask-repudiators. In the case of the Trumpians in the US, I'd compare them to victims of a cult. I'd pity them before I'd hate them.