Laws are a form of applied ethics, and mere tools to make right things happen.
Therefore laws have no power to determine what is truly correct or not.
Sexism and racism, for example, had been legal for a long time, but the wide agreement that they are actually morally wrong led to illegalization of such discriminatory behaviors.
Ethics always comes before laws.

An action is 'a personal choice' only when there is no victim.
Creation of someone means creation of the root cause of literally every single thing that happens to them in their life, which is their very existence.
This is clearly not 'a personal choice.'

An action is 'a personal choice' only when it affects no one negatively.
Paying for animal products means outsourcing the violence of creating, torturing, and brutally killing non-human animals.
This is clearly not 'a personal choice.'

Humans and non-human animals never to be created cannot have any rights because they do not exist, and therefore could never have their rights violated.
Only we, already existing painients, have rights, and as a result, get exposed to the chance of having our rights violated.

Who exactly does antinatalism take the opportunities away?
Humans and animals who are never to be created, literally, never exist, so they cannot be deprived of anything.
Moreover, even if we create them with the goal of giving them a happy life, there is no guarantee that it would definitely work.
If it fails, the created one gets harmed.
If it succeeds, the act of creating them only turned out not to be wrong purely in terms of results, but it is only 'not wrong' in the same sense as it is not wrong to throw a rock down a mountain, which happens not to hit anyone.
The wrongness of the gamble of creating them remains true regardless of the result.

It is true that, when one experiences a lot of pain and subsequently regret being created, they are in a position where it is easy for them to realize the legitimacy of antinatalism.
However, the fact that the person regrets being created has no impact on whether antinatalism is correct or not, just like racism is wrong no matter who says it is wrong; whether it is a victim of racist treatment or not does not matter.

Furthermore, this response to antinatalism seems to presuppose that we should, or can, create those who would have good lives even if it risks creating those who would have bad ones, which is a utilitarian mistake where the well-being of an individual is sacrificed for the benefit to many.
 

Whether someone can give the consent to being created or not does not determine whether we need the consent before creating them.
If the impossibility to ask for consent means the absence of need to ask, then it should be acceptable to have sex with someone who is too drunk to give their proper consent.

If you create someone, the harm of creating them without their consent is done.
If you do not, however, then the person who you do not create literally does not exist, so they cannot be harmed by having something done or not done without their consent.

You and your descendants are separate entities.
They will not necessarily experience the same things as you do in their lives.
Even if they did, how much pain or pleasure they experience would vary from one person to another.
However highly you rate your own experience in life has no impact on whether you should create a new person or not.

It is indeed natural for us to procreate, but does 'natural' mean 'morally correct'?
If it does, then things we consider to be obviously immoral such as murder, assault, or rape, should also be morally correct.
What is natural is not necessarily ethical.

Regarding the morality of inflicting pain on someone in order to help their growth, there is room for discussion if we are talking about already existing humans or animals; for example, it is widely considered acceptable to force human children to go to school and to have a hard time, as a means to help them survive the society in the future.
However, when it comes to those who do not exist yet, they simply do not need to learn and grow, because they do not exist.
It is only if we create them that they will find themselves in a situation where they are in need of growth.
Creating needs where there were none and causing pain to the person with those needs is clearly irrational, and no justification for procreation can be found here.

That is not a reason to allow creation of new painients.
The created one would experience not only some pain that serves that purpose but also some that does not at all.
Even if they fortunately avoid going through such meaningless pain, they never should have needed or wanted to experience pleasure.
Creating someone so that they can experience great pleasure is entirely irrational.

Giving up on doing the right thing just because you have made a mistake before is the same kind of dishonest and evil way of resisting change as telling yourself you don't deserve to be a safe driver and driving erratically just because you have caused a car crash before.
Whether you have a clean license or not has nothing to do with whether you should drive safely.
All we can do is make the future better than it otherwise would be, unless someone develops a time machine.
Some anti-sexist activists would have been sexists themselves; some vegan activists would have been deeply ashamed of their past where they sustained their body by consuming animal products.
Nothing about their past can make them fake anti-sexists or fake vegans.
The same applies to antinatalism.

Giving up on doing the right thing just because you have made a mistake before is the same kind of dishonest and evil way of resisting change as telling yourself you don't deserve to be a safe driver and driving erratically just because you have caused a car crash before.
Whether you have a clean license or not has nothing to do with whether you should drive safely.
All we can do is make the future better than it otherwise would be, unless someone develops a time machine.
Some anti-sexist activists would have been sexists themselves; some vegan activists would have been deeply ashamed of their past where they sustained their body by consuming animal products.
Nothing about their past can make them fake anti-sexists or fake vegans.
The same applies to antinatalism.