TL;DR: The problem is that it's not really a problem of reason but a conflict of interest.
It's somewhat like as if you'd ask a scientist whether it's warm outside. Like they can tell you the temperature (to a reasonable degree of accuracy) and if you give them a reference to work with they can tell you whether it's warmer or colder than that, but they can't tell you whether you'd think it's warm. For all intents and purposes it could be temperatures like on the surface of the sun and their last words, before turning into charcoal, could be "Would you mind turning on the radiator, it's really a little cold today"...
So you'd need to have a commonly accepted temperature range that is called "warm" for a scientist to meaningfully tell you whether it's inside or outside of that.
And a similar problem applies to the philosopher here. If everybody just states their opinions and only provides reasons that work for their frame of reference but that are incongruent with the frame of reference of other people than it's almost impossible to make something out of that. In other words it's a political struggle where you're supposed to pick sides not really a logical one where the answer reveals itself to you after deep thought. Edit: By deep thought I mean checking the arguments. The problem is that people don't even agree on the premises.
Like the first question might be if the interests of either side are even valid to begin with. Like for the pregnant woman and the fetus it's obviously quite an existential issue, but what about the bystanders voicing their opinions? Anybody from the person co-causing the pregnancy to a completely random bystander.
For them the issue is way less existential (if not to say not at all), but they could take on the role of a guardian of the fetus. Which isn't unusual that people who are not or not any longer able to speak for themselves are protected by someone taking the role of a guardian. So if you'd take this conflict of interest to court, they'd act as a lawyer.
So now the question is "is the fetus a human" for whom this protection of human rights would apply? Which prompts the follow up question of "What does it even mean to be human"? And "Where does being a human start and where does it stop?". Like children are not particularly bright or developed (yet) but they undoubtedly count as humans (agreed upon). So does being a human start at birth?
What about things like drinking during pregnancy and giving birth? In that case you'd have harmed the child without having harmed the child, because while you were doing it there was no child yet you were aware that there would be one and that you would hurt that. So is it purely self-harm or is harm to a soon to be human that caused by harm to an actual human and therefore already something that should be ruled as unethical.
Now that is only tangently important to abortion because if the pregnancy is aborted there is no human to be soon after, but it's something that could justify protection of the fetus before birth. Meaning the goalpost could be moved from protecting a human or "actually soon" to be human to preventing harm. So you could argue with the point of viability either in terms of "being able to survive on it's own" (premature birth) or at the point of "if there's no external damage the thing will likely make it and not be lost during pregnancy naturally".
Which is a question that might even be answerable, in the sense of that you could map out a time scale or stage of development upon which the perception of pain develops. I don't know when a brain or central nervous system is formed. Something like that.
Whereas if you follow the soon to be human trail you would come to the question of where humanhood starts. Which could either lead to the question where life starts or where humans deviate significantly enough from other species. Like if you argue that any human embryo always develops into a human only then it might be when life starts, while if you argue when it starts being human you might again have a cut off range.
But mind you all of these concepts so far only deal with the question of whether or not other people or society would be ethically valid to take on guardianship of a fetus. It has not yet made any decision in terms of deciding the actual conflict of interest between the woman and the fetus. And which sides claim to life and harm prevention is actually more important.
Like you could argue that all life is valuable and saving a life is worth the harm to another. But then again are we consistent in that? Like many of the same states that have anti-abortion trigger laws also have the death penalty and enforce it. Or the fact that we regularly eat species with more developed pain perception for lunch.
So it can't be live itself and there are apparently situation where it's ok to kill people and it's not even for immediate harm prevention, like those inmates are not really in a position to hurt people.
So while hypocrisy does not mean being wrong, being right would trigger a whole load other consequences that we currently blissfully ignore. Animals rights and whether personhood can be a thing in other species and how we should address that and aren't and many more.
So on the other hand you could also argue that the woman is obviously more developed than the fetus and so is much more capable of feeling pain and being harmed and incapacitated by the pregnancy than then fetus. So even if you granted the egg and the sperm cell full personhood you might still argue that it's more like putting down a pet or even less than that as a pet is already developed much further than the actual fetus.
So in order to give a useful answer on whether it's warm you need to somehow decide one of these questions, because otherwise those are questions of moral frames of reference that take on the shape of religions where you can't argue with them unless you accept their premises and so you need to decide what you agree upon.
