It really doesn't matter what anyone believes at this point. I'd consider myself an efilist, which is essentially a step further from even antinatalism, but it hardly matters much. People are programmed to spread their DNA, so that's what they'll do. It's likely that nothing I, or anyone else says will change their minds. Relativism reigns supreme here. There's simply no way around it. People of one temperament will find certain ideas palatable to them, while others of another kind will, of course, feel differently and instead find something else that's more suitable to justify whatever their established worldview is.
Overall however, to condemn an entirely new person to life on this planet, is the sort of thing that seems pretty hard to justify. Especially nowadays. The only two guarantees in life are suffering and death. Happiness, contentment, joy, pleasure. None of these things are promised and, at worst, only rarely present themselves. Why anyone would think such a thing is worth passing on is beyond me, but whatever. It's not like procreation is much of a rational/benevolent act to begin with. After all, kids can serve many purposes. They can temporarily pump up a failing relationship the way you would a flat tire with a hole in it, endow the parents with a sense of meaning, provide free labor or insurance against old age, allow the parents a renewed license on youth, validate their ego, or any number of other fundamentally self-centered things. This is of course assuming any thought was put into the act at all and wasn't just a random byproduct of unprotected sex, as it tragically so often is. Well, again, people are going to do what they do. Like frogs laying eggs in a pond. Go ahead and continue to fill up the world with new agents of suffering. The more you do so, the more the process of our extinction is quickened along.
And, honestly, that's really the crux of the matter. Our planet, and our civilization, are dying. This is an indisputable fact and a reality you simply can't escape from having to consider, unless you're flat out in denial. For anyone out there who does want to have kids, you have to know that they're gonna die far sooner than you ever anticipated. Please keep that in mind. Do you really want to see your kid die and have to suffer in a world currently experiencing omnicide? Despite what you might believe, you won't be able to protect them, and, in all likelihood, they will die an early, agonizing death. Your child will be just another victim of the meat grinder we've now set to chew ourselves, and everything else, to pieces. Forget about all the philosophy or ethics that surround the topic, even beyond suffering and death, the fate of your child is already set in stone. What good does it do them to experience a quality of life magnitudes lower than the one that currently exists today?
I should think that such warnings would be sufficient enough reason for many to re-consider procreation (which, fortunately, seems to be the case), but just as many, if not more, will choose to go ahead with it anyway. Much to the detriment of both themselves, and especially the children they coveted the presence of so damn much. And that they will now have to see succumb to a world not capable of sustaining either them, or any of us. Just know that you could've avoided this and, perhaps, if you're able to rise above the unjust need your DNA first imposed you with, still can.
Below is a very relevant video that I'd highly recommend watching; especially to anyone who's skeptical of either the end of the biosphere's ability to sustain our species, or antinatalism/efilism as a concept worth taking seriously.