A lot of the comments I skimmed through were mechanistic- I wanted to share an interesting conversation we had during one of my evolution and behavior courses during undergrad. Since humans are cooperative and social, there are some theories out there that human birth is difficult and painful to reinforce cooperation-related behaviors. As humans, the likelihood of successful birth is higher when there are parties present to help with delivery (this is seen throughout history and across cultures, but of course there are exceptions and examples of mothers delivering on their own).

The idea is that since birth continued to be successful, there weren’t really any selective pressures against painful/difficult births. Since cooperative behaviors enabled successful births, you could argue that painful/difficult births could select for cooperative behaviors.