That's a bit arbitrary though, isn't it? I mean, are newborn babies really people? The Romans didn't think so. I don't see the big philosophical difference. They can't earn money or pay taxes, and are 100% dependent on parental care and resources.

And how about sleeping people? I mean they're unaware of their surroundings. Are sleeping people real people? Sure, they'll inevitably wake up in a few hours, if nothing goes wrong. Same as how a fetus will inevitably develop into an adult and be fully conscious, if nothing goes wrong.