Also most children died before adulthood.
If you are affluent with each additional kid the risks more rapidly outweigh the rewards. Since all of us are generally more affluent now it is quite sensible to avoid having many kids.
The history around childbirth is really very brutal and grim. We should be having less kids. It's a positive sign for our species, like having less blood spilled over religious conflicts.
People who have kids because they don't know what else to do with their lives are probably raising children that are going to turn into unpleasant adults. I'm not sure why I would want to incentivize more kids where I would not relish the parents undergoing mitosis either. If someone wants to reproduce have at it, but why should I be excited by this? If "hell is other people" then what are other people's kids?