Simply not perfect? No. Can see a path to it though. Equally might that be a poor analogy? Potentially decades of experiences, connections and such compared to potentially nothing and in all but the most extreme cases then effectively nothing.
So you reckon conception (as opposed to simple gametes, or implantation -- the egg may be fertilised long before it is implanted in the uterus, the being methods also to prevent implantation) is the line? You say it is a religious debate. I don't believe in your religion and general philosophy of law these days is keep religion out of it, and while people to free to vote being influenced by their religion there are fundamental aspects of said law that will override what an implementation of the religion would see put in place on the grounds of various kinds of freedom. Why then is your religion, or indeed your interpretation of a religion, relevant to me or the law of the land? When then not got with "If you don't like one then don't have one"? Equally on the face of it your religion is potentially thousands of years old and unchanged during that time, and features all sorts of things one might find extraordinarily distasteful today, to lean into that would surely be an odd thing to do.
It is possible that it is the case but "muh religion" does not work for me in this. We can come to an agreement that stealing items is bad because it deprives the owner of their resources, no need to worry about what some old books or groups of people that like to read old books say.
Either way I find lessening suffering to be the better choice for figuring out something, and it is the thing that informs most of everything else in finance, philosophy, law and indeed much of religion for that matter if you are coming from there. This is also why we end up with a more complicated process that looks at the potential troubles for the host and the would be unborn.
"You can't 'offer reasoning' to something like life"
Humans can create it in a lab now --
https://www.theguardian.com/science/2010/may/20/craig-venter-synthetic-life-form
Stack enough inert chemicals together and you have something that conforms to most definitions of life used -- reproduction, consumption of fuel, response to stimuli deriving internally (
http://www.ibiblio.org/jstrout/uploading/potter_life.html ).