You talk about “complexity.” That’s the point. A cake is much more complex than the ingredients it is made out of. And so is a fetus. What is a fetus made out of? An egg, a sperm, and the fuel of the mother’s blood over a period of approximately 40 weeks, nurtured inside of the womb.
Everyone knows you can’t quit baking at the mixing phase, call it a day, and turn it in as a cake. Nor can you mix the ingredients and give up before you pour it into the pan. Nor can you pour it into the pan and neglect to put it in the oven. Nor can you neglect to take it out of the oven. We intuitively grasp all of this.
And, as you say, a real person is infinitely more complex. I agree!
Put simply, it takes *work* to turn a fetus into an infant. Important work, highly personal work. Work that the government has no business mandating anyone perform. There’s even a word for the last crucial part of that journey: “labor.”
(Side-note: The critical, intense, and sometimes dangerous birthing process has of course been completely written out of the equation of creating human life by “pro-lifers,” reduced to less than a footnote. Under the cake analogy, that’s like saying taking the cake out of the oven is totally irrelevant.)
And what is forced labor? It’s slavery.
That said, we recognize that a cake that is 5 minutes from being pulled out of the oven is “more of a cake” than the unmixed egg and flour that it started as. It has a stronger claim to being called a cake, by that point, regardless of the baker’s feelings on the matter. And that’s fine. That idea supports a ban on 3rd trimester, and so-called “partial birth abortions,” which states have *always* had the ability to ban, even under Roe v. Wade.
But by banning abortion from the moment of conception, under all circumstances, which is what most “pro-lifers” want these days, the state turns women into literal slaves. It keeps them trapped in the kitchen for 40 weeks, and indeed, for 18 years after that, if they’re unwilling to give up for adoption what the state forced them to bear.
That viewpoint can only result from seeing women as birthing and nursing centers, primarily, and not as fully-fledged citizens with their own legitimate dreams and aspirations.