I don't think I agree. I frequently go to bed much later than I should and can function on very little sleep. But it's bad for me and probably makes me age much faster.
A visualization of how much sleep I'm lacking in order to satisfy some basic sleep requirement would help towards alerting me to go bed earlier.
Also if I'm doing something to improve my quality of sleep (meditation, no digital devices an hour before sleep) it is rewarding to see that I'm sleeping longer and deeper.
Your reasoning can also be used to dismiss exercise tracking. You just exercised and you know you feel like you put in sufficient work. What's the point of knowing if you "competed a circle"?
As it happens I don't track my exercising either, I go to gym and do exercises simply because I know it's good for me and that as an IT worker my job is too sedentary. Maybe if I was working towards a competitive goal (run a marathon or do a triathlon) I would track as iterative improvement would be necessary but I'm not so I don't. Equally I don't have competitive goals for my sleep cycles.
I agree with you in principle but as someone with bad habits (not getting enough sleep) I think the watch can help as a guide to change those habits and live a healthier and longer life.
For whatever it's worth, there are some studies that suggest that even if you work out every day, sitting for a consecutive 8 hours a day will still shorten your lifespan. So a watch might remind you that you've been sitting to long and to take a 5 minute stroll.
fwiw, Apple watch does actually remind you to stand up and walk around once an hour if you haven't. I've actually found it a nice reminder. I can tell when i get the buzz that yeah i've been sitting too long I should get up and walk around.
A visualization of how much sleep I'm lacking in order to satisfy some basic sleep requirement would help towards alerting me to go bed earlier.
Also if I'm doing something to improve my quality of sleep (meditation, no digital devices an hour before sleep) it is rewarding to see that I'm sleeping longer and deeper.
Your reasoning can also be used to dismiss exercise tracking. You just exercised and you know you feel like you put in sufficient work. What's the point of knowing if you "competed a circle"?