Have we really lost the sense of wonder of what it means to even POTENTIALLY bring another human being into the world?
You might, but not everyone shares you views. This is why it should be about choice.
Even if I accept that an unborn child is not a "person" until 24 weeks post-conception (a notion I reject), is there truly no sense of wonder that the genetic material growing in a womb will, given enough time, grow into a sentient being like ourselves?
It doesn't matter. If it will become something, it isn't that thing right now. That is the nuance that is important. Heck, why must there be fertilization? Sperms and ova have the potential to become humans too. Why not protect them too? What about cloning? Every cell in our bodies has the potential to become another human? Is cutting nails murder? But personhood isn't really important in this debate.
It always has been about sovereignty over one's body. If a father can't be forced to give his blood to his dying two years old who needs a blood transfusion to live, because he is the master of his body and decides what happens to it, why should a woman should be forced to give her uterus to a mass of cells who will die without it, whether it is 24h after conception or 24 weeks after conception? Why can't she be the master of her body, but other people can? The life of someone else doesn't matter in one case when sovereignty over one's body is involved, why should it in another?
Now if living adults where forced to give organs, blood and bone marrow to people who need them to live, there would be more coherence. Organ transplant is dangerous and risks should be taken volontarely? Ok, but pregnancies and labour also involved risks. Why not use the percentages of chance of death and injury from pregnancies and labour to see which organ donation is as or less dangerous and force those on to people too? But why use pregnancy as the barometer? Why not kidney transplants or liver transplants?
I also think the "chicken and egg" comparison is something of a straw man argument. Do we really want to make comparisons of the relative "potentiality" of personal thought, experience, creativity, and animus of a chicken versus a human being?
It is a analogy. But humans and chicken are both animals, this is why they can be compared to certain degrees. The idea here is to show that potentiality doesn't mean you are that something. Like a caterpilar ain't a butterfly, a zygote ain't a person. If you want to say that a zygote is a person, and not based on its potential to become one, that is another matter.