But being childless in your golden years is guaranteed misery.
Yeah. This isn't reason number one to have kids, but being surrounded by children and family every holiday, on special occasions and events, it's really great. And when you get old, maybe your kids take care of you, maybe they don't, but if you have no kids, you are pretty much guaranteed to be miserable if and when your health declines.
Anecdotally, and counter to the other poster's anecdote about kids leaving their parents to die, in December of 2016 my MIL's kidneys failed. She moved in with my family, and found out in January of 2017 that her breast cancer had returned, and she was terminally ill. My wife and I cared for her, and she spent every day with her daughter, her son-in-law, and her grandchildren except her very last night before she passed in March of 2017. I can't imagine going through that with little or no family support, dying alone. And it actually happens, I see it at work, oftentimes childless people dying unattended deaths and rotting for days.