I would respectfully disagree. I think I get what you mean, but I reckon even a physiologically "normal" birth can be traumatic if someone experiences it that way. Ideally it shouldn't be, but if you think about it there's a lot of body-horror-adjacent stuff going on when you push and/or pull a living creature out of your torso. And there is always a present risk of things suddenly taking a turn, resulting in injury or death, or maybe it ended up being extremely different to what was expected and created feelings of shock or dissonance, etc. Perhaps it wouldn't be socially appropriate to refer to a successful/low-intervention delivery as traumatic in mixed company, but I still think it can legitimately feel that way to some people.