Gene editing on humans is certainly a can of worms, but the ethics there are a bit less direct. Its more about a slipper slope than the effects of any one person making the decision.
It is particularly hairy when your modifying your kid who is too young to consent but will be effected by a lifetime. But at least with gene editing, for the most part it is done in the best interest of the child, with an abortion you cant really make that argument,in fact very much the opposite, sacrificing the child for the good of the parent.
We are no where near ethically mindful enough as a species to engage in gene editing ethically. Sadly we **are** quickly approaching the point where gene editing is necessary for the species to thrive at all. It is a dangerous cross roads to be at for sure.
It is neccesary due to how genes evolve and work overtime. As medical science is able to treat genetic disease better and give someone a normal lifespan with an otherwise debilitating disease then that disease is no longer selected against very strongly and can proliferate throughout society.
So the end result of modern medical science is, over time, genetic diseases becoming more common until you have a future where everyone is wheelchair bound with cerebral palsy, half blind and only able to see with medical devices and effectively on life support from the first day of their life. This gives a rather concerning quality of life for future humans if we dont ethically implement gene editing before it gets to that point.