At this point, if I don't have a phone with a good camera, I'll have to go buy a new standalone camera- probably a point&shoot- in order to satiate my need for documentation and taking photos of my kids.
Also, nobody here seems to mention convenience- carrying around a smartphone is a great replacement for the calculator, watch (possibly with an integrated stopwatch, if you don't get anything too fancy,) walkie-talkie, stress toy, fidget spinner (there's an app for that), elephant, newspaper, or tabloid that might otherwise be on their person.
Also, nobody here seems to mention convenience- carrying around a smartphone is a great replacement for the calculator, watch (possibly with an integrated stopwatch, if you don't get anything too fancy,) walkie-talkie, stress toy, fidget spinner (there's an app for that), elephant, newspaper, or tabloid that might otherwise be on their person.
Utility!