You obviously do not know much about embryology. It takes a few days for a zygote to become a blastocyst and a blastocyst to become an embryo - if it even lives long enough for that to happen. God kills most human zygotes and blastocysts. He also kills many human embryos. So the chances of a zygote eventually looking like a person would be under 50% even if nobody ever had an abortion. If all humans get their souls at fertilization, why would God kill them less than a week or month later? Also, embryos are nothing but groups of stem cells very early. Organs, hairs, bones, tissues, and body fluids start to form, but the human appearance starts when it becomes a fetus.
People with cerebral palsy and amyotropic lateral sclerosis (ALS) can do more than embryos. The same can be said about people with many other disabilities. Embryos do not even know about their own existence because they have none of the five senses or the ability to think like the vast majority of 8 billion people.
In the case of comatose people, they had the right to choose death instead of life support. There is no law forcing them to remain alive against their will. Doctors do everything possible to keep them alive if they do not have a living will with specific instructions to let them die instead. Unfortunately, most people do not think about getting living wills before they need them, which causes hospitals to waste thousands of dollars treating people who should not be alive.
What don't you understand about the difference between "human" and "person"? Those two words never meant the same thing. The definition of "person" has always meant a born human. I could not have been more clear about that. Everyone who went to a school in America knows it. The only reason anyone ever says unborn humans are people is they want to believe that, not because that is what they learn in school. They wish the extremely obvious, repeatedly proven, totally necessary and loving truth in America was fiction.
The right to life never existed for unborn humans in America. It has always been exclusive to people. The Fourteenth Amendment codified that fact to prevent unborn humans from ever having the right to life in America, but that was just a formality. No unborn human beings were ever, in all of American history, considered people or given the right to life.
A picture is not the same anymore when it becomes defective. It is still a picture of humans, but not a picture of perfect humans - which are what God created after He said, "Let Us make man in Our image."