Give one reason why you do anything you do without "I want".
Wanting something isn't selfish. It entirely depends on what it is you actually want.
Oh yes, you could argue from a hardcore libertarian stance that altruism does not exist and every action is inherently selfish but is that a good way of looking at the world? I think not.
If it's an accurate way of looking at the world, you've just demolished your own reasons for not having kids.
You don't want kids because it's selfish? That must mean, using objectivist reasoning, that to you not having kids is even more selfish. So your reason for not having kids is no reason at all if you subscribe to that sort of shit.
As for good, in the same way that you reduce a lot of things down to one thing that is objectively true but isn't really useful for everyday life.
Sure, I accept that it's possible to reduce down and argue all behaviours are selfish. Does that provide insights about the world? Nope. Does it explain human behaviour adequately, even if fundamentally accurate? "Why does inequality negatively impact inequality?" Because people are selfish?
On the flip side, there is some probability that your child may save 1 or more lives.
On the flip flip side, there is some chance your child may take 1 or more lives.
Arguing about the selfishness of procreation is silly. It is your biological purpose. Whether you choose to run with that or not is down to you. It is not selfish if you choose whatever way.
As a parent, my children come first. I would die for them. You make that choice when you have children. That is NOT selfish.
Give one reason to have children that doesn't include words like "I want".