I think its a given that Garmin sleep tracking is not as good as others, but I think there could be a simple fix for this. I've noticed that if I go to bed and watch a tv show/movie, or if I wake up and spend an hour or two awake but trying to sleep, it's recorded as being asleep. Not just recorded as sleep, but often deep or REM sleep. This really over inflates the sleep score making it pretty much useless.
It would be beneficial if I could go in an manually adjust some of the stages to show when I know I was definitely awake, but in bed. I would think Garmin could then take this data (recorded vs actual), run it through some machine learning AI to tailor the algorithms on the individual level assessment, or the community as a whole.
Seems like it would be a simple field to add, which would also provide Garmin with some valuable real world data that could be used for improvements in sleep/wake accuracy.