Personal experience: I got hooked on hitting my activity goals with my Apple Watch and am now on day 292 of my streak. I've lost 20 pounds and am running a 5k at a near 7min/mile pace, something I haven't done in over 15 years.
Sure: the watch didn't move my legs for me, but it sure as hell manipulated me into getting off my ass :)
Counterpoint, I never want to run at 6:30 am so having someone or something add pressure to get out only helps keep that commitment. And 15 min in I'm always glad I got out of bed.
Different things work for different people. My wife and I exercise very regularly, but the way in which we stay motivated and on track are very different.
Not sure if the Apple watches do the same, but the Garmin watches have a "Move!" reminder plus easy-to-configure step and stair goals, and make your progress obvious. I'm guessing it's more due to those types of little pokes throughout the day than parent actually forgetting to hit the gym every morning.
AW does this if you don't stand up within an hour, it pokes you to stand up and move around. It also sends you progress updates throughout the day of how much you've walked/moved/etc.