The world doesn’t need extreme antinatalism as a philosophy when reproductive rates are already plummeting across most, if not all, developed countries. What we do need are full reproductive rights, freedoms, and sex education for both men and women in order to have the birth rates of every country where humans live reach a sustainable level. Full access to birth control, contraception, family planning, and abortion services will help control the birth rates.

Mercy killing someone would leave their loved ones behind to grieve them. Merely refusing to get pregnant or to impregnate anyone else doesn’t cause any loved ones to grieve the loss of an already existing person.
However, forced mass sterilization could become an option that antinatalists could use to prevent any more future births and thus prevent end more future suffering, even though it would also deprive people of bodily autonomy and the choice of whether or not to reproduce. A lot of antinatalist groups might think that forced sterilization could be acceptable if it was applied to everyone.

Keep in mind that we know of no habitable world other than Earth with life on it just yet. If there are sentient beings on other worlds, then they might have a more nuanced and enlightened understanding about the morality of reproduction that we do. It is human arrogance to assume that reproduction is a net negative based purely on our own understanding of what suffering is. Efilists and antinatalists seem to believe that other forms of life could come to the same conclusion that they did if said forms of life were intelligent enough.

Death in childbirth is a risk that can be mitigated and reduced by professional obstetrics, as you should know. The countries with the highest rates of maternal mortality also have the worst national health care systems or no nationalized health care systems at all, so humans already know how to systematically reduce maternal mortality rates without completely banning human reproduction. Politicians in those countries just don’t care about women.
Lots of neurodivergent people lead happy and well adjusted lives. Who are you to decide that their lives aren’t worth living?

1. Nonexistent people are unable to say no to being brought into existence either. You can’t necessarily predict what the future person wants based on what YOU believe is true. The future person may have his or her own opinion on the matter once the person becomes an actual living human being.
2. We subject ourselves to potential harm all of the time every time we eat or go for a walk in the neighborhood. We run the risks of choking, getting food poisoning, or being hit by a car in the street. Yet those are necessary risks that can be quite easily mitigated while still allowing us to enjoy the risky activities. We subject our children to similar easily mitigated risks by sending them to school on a school bus, yet we consider school to be necessary for children.
3. Procreation is not actually inherently immoral by itself. It’s not inherently moral either. It is a risky activity that depends on the context. We mitigate the risks by ensuring that the children are born into safe environments that could adequately care for them.

Nonexistent people are unable to withhold consent as well. In a fantasy thought experiment, if I was to turn a fictional character that I created in a story into a real person, the character wouldn’t be able to say no to what happens to them. Same thing with conceiving a baby and carrying the baby to term: the baby could not say no to being brought into this world. They don’t have any reason or capacity for withholding consent, and we often give children medical care without their consent on the basis that the care is in their best interests.

If souls exist, then it could also be possible that they consent to being brought here more often than not. If souls exist and if they really LIKE to be incarnated here, then it would be in their best interests for human reproduction to continue. Reproduction becomes inherently moral on that basis as well as on the basis of continuing the species.

If souls don’t exist, then the argument of bringing a nonexistent person into existence applies: there is no one who could refuse to be brought into existence. Thus reproduction of sentient beings is inherently amoral on the basis of consent rather than immoral. Morality doesn’t really apply to basic instincts.

The only person who consent applies to in the latter case (souls not being real) is the mother who wants to give birth, and we should never violate her bodily autonomy.

Working for pleasure reduces suffering, doesn’t it? If it serves the community and makes lots of people happy, then suffering is reduced.

How would you prove that genuine happiness and joy are illusions? Why would they be illusions if they serve a purpose in this universe? The burden of proving your claim is on you.

To be clear, actual “Nihilists” like Nietzsche were against nihilism (so their being called nihilists is a misnomer).

So when one says something like “according to nihilists” you need to be specific: who is saying the thing you mean?

For example, Nietzsche said nihilism is a state one would incorrectly arrive at if one followed natural reasoning, but he never identified anyone who ever actually did that. And Nietzsche’s argument was that because values and meaning don’t exist apart from human choice, individuals need to construct and accept their own value and meaning rather than be duped into having someone else’s values or meaning imposed on them.

So you can’t mean Nietzsche. He’s more correctly described as a radical relativist, not a nihilist in the sense of embracing nihilism, but defying it by personal will.

So who are these actual nihilists you are attributing views to?

Etc.

Indeed. I just covered these distinctions recently (since it’s coming up with AI hype now).