Is it? I imagine the mortality/morbidity rate for women before modern medical interventions during childbirth was much higher.
My wife had to have her amniotic sac manually broken by the doctor after 12 hours of labor to resume her dilation.
I agree, mortality was most likely higher because when complications happen, modern intervention is much better, cleaner, we know about bacteria and other stuff exists and stuff like that.. but that's only like 10% of the cases(anecdote).
About your wife: if you take a woman in labour from home to an unknown place where strangers stare at her vagina and put stuff in guess what happens? Labour stops. Now you need artificial stuff to make it happen regardless - drugs, breaking sac, more drugs, suction cup, whatnot...
My problem is that we butcher the 90% of cases where there is no need for any intervention to the process.
Data would be nicer than anecdote. But even at 10%, if you are a woman, at 10% probability of needing experienced professionals with medical training and equipment, are you taking a chance at home or at the hospital?
More common than mortality is morbidity, and evolution does not quite care about that as long a woman survives well enough to procreate again. But women themselves most certainly care about hemorrhoids, tears, pain, infections, etc.
Back to the point though, if the implication of comparing it to vomiting is to say that the mechanism is "simple" enough so as to be reliable enough to not need intervention, I think most women would disagree and prefer having intervention available if necessary. Perhaps many interventions are unhelpful, or the tradeoffs not worth it, but many are helpful, and the medical field does seem to eventually abandon the bad ideas once shown unhelpful.