Maybe the OP has got a point actually about the parent vs non parent thing.
When I was pregnant with my son I could have told you at any given time what fruit he was the same size as this week, and I could feel him kicking up a storm in there, and he had a name, and I had had a million scans, but I still couldn't wrap my head around there being an actual human baby inside of me. If you have a miscarriage at 7 weeks it looks like a prawn, and if you end up delivering your baby at around the viability cut off point, it doesn't look quite fully formed (whether it is born alive and very premature, or is stillborn). But at some point between then and 40 weeks it becomes a lovely, fully developed little baby with soft skin, who could be born at any time and look, well, like a normal newborn baby. When I was holding him in my arms I couldn't wrap my head around the fact that the day before he'd been just as pink and perfect, but still on the inside, suspended in liquid.
Second time round it was a little bit easier, but instead of looking at my app and learning that my daughter was the size of a papaya this week, from about 22 weeks onwards I started searching Google images for "baby born at 22 weeks" and so on. I know it sounds really weird and kind of morbid but I had this need to know what the baby inside me actually looked like right now. And when I got to about 30 weeks, I was Googling "baby born at 30 weeks" and getting pictures of babies who looked perfectly normal, if a little on the small side. That was the only way I was really able to comprehend it.
Just speaking from personal experience but I can see how someone who had never had a baby before might struggle to get their head around the idea that if you support a woman's right to terminate a healthy pregnancy at, say, 30 weeks, you really are just saying it should be legal to kill a pretty much fully developed newborn baby as long as it happens to still be on the inside. (Sorry if this language is triggering, it's not meant to be.)
I suspect that some people who have never given birth conceptualise pregnancy in a rather abstract way, like for example your Uber Eats app is telling you your pizza is on its way but you don't think of it as being a real pizza that actually exists until it's delivered and you can actually see, smell and taste it.