That’s a bit tongue in cheek. Then again, I didn’t wear watches before; time alone didn’t seem a good enough reason. But that, combined with other benefits, works for me.
In the first months after starting to wear a watch (smart Apple or any other kind, really), I kept forgetting that it also tells the time. The habit of looking up the time on the phone was so deeply ingrained, if I tried to find out the time while in a bit of autopilot mode, I'd always reach for the phone, instead of looking at the wrist.