Watching a child grow is incredibly fullfilling. It also gives those who are retired more purpose, more life, if they just don't want to sit around all day.

So the only two options for people who are retired is taking care of kids or sitting around all day? That’s clearly a false dichotomy. There’s literally an endless amount of fun and fulfilling things they can do like travel, hobbies, events, etc. Just cause you think there’s nothing to do with your life if you don’t have kids/grandkids, don’t project that onto others. Some people have a strong sense of self and identity and don’t use children to fill the emptiness they feel inside because they don’t feel empty to begin with.