When I had a kid, I found myself taking a lot more photos. When a baby lies on its back considering a ceiling fan for half an hour, you can suddenly find yourself with dozens of cute shots. And it doesn't stop when they grow up.
At a certain point, this bounty of photos weighed on me. I would look at my photo library on my phone or computer and worry about what would happen if something went wrong. It was time for a backup methodology more advanced than plugging in an external drive a few times a month.