It is stressful to be a parent and it's not easy, but it's all well worth it. No one told me I "had" to have kids, I wanted children because I wanted too. I was told it was difficult, but that didn't stop me, it was a personal choice that I'm very happy with, I can't imagine my life with my "stress" causing children, they mean the world to me, they are my joy, my everything.
I don't think children bring marriages down, adults do that to themselves they are the ones to allow it, but the easiest person to blame it on is the kids. Children don't cause depression, it's just easier to blame it on the kids as well. Everyday life, whether someone has children or not, is full of stress, traffic causes stress, work causes stress, being on hold on the phone causes stress, making a long line causes stress, going to the bank causes stress, let's blame children for that too, it's their fault, without them probably all those stress factors wouldn't exist.
Was your mother forced to have you? Do regret the fact you came into the world? Do you wish your mother would have said, I don't want the stress of a child, let me not have my daughter.
By the way not all children turn out to be serial killers! What's your problem? Word of advice, don't have children, please! If you don't want to deal with the "problems" having children brings, just don't have them, no one is holding you at gun point forcing you to have children.
While you're young, you might enjoy being young, traveling with your significant other, spending time together, but when you get older, and have no energy left, and your partner leaves this earth, guess what, you'll be left all alone, then you'll be wishing you would have had that stressful, depressing life with children of your own.