The thing is, you can’t predetermine if they’ll have cancer or some other rare conditions before existing. There’s very good screening tests nowadays to help prevent that as well. To me, it seems like a strange morality for that to be your reason to avoid having children. It’s anticipatory grief, like not making friends because they might die. By the same logic, what if your child is the one that discovers the cure to cancer? In that case, it’s cruel not to have them, but you can’t know, so it’s a moot point. Unless you do know, in which case send me a DM, I’m in need of a mystic.

Hereditary conditions are a whole different conversation.