Recently at least 2 people we know found themselves with a broken iPhone and everything on it was lost. The most painful loss in both cases was all the photos on the phone. We've become a nation of phone picture takers, leaving a camera behind.
Obviously it pays to have that phone backed up either on the cloud or computer. That way if your phone breaks you'll have a way of getting to the pictures. But so many of us don't do that as regularly as we should. At the very least your settings should be set to automatically save pictures to iCloud as well as the phone. That way they're accessible. Or, once in a while get them onto a computer folder.
But in the end, the best case for taking pictures of things you want to keep, special occasions, etc, bring along a camera. They make good cameras these days which are not much bigger than a phone. Just toss it in a pocket or purse. Then lenses will be better as well.