Crystal Cox/Business InsiderOf course, in order for the Apple Watch to serve as a better sleep tracker, it'll have to offer longer battery life.
The Apple Watch Series 5 can comfortably get through a full day and then some, but Fitbit devices are capable of offering multi-day battery life. That means if you plan on using your Apple Watch to track your sleep, you'll have to remember to find time throughout the day to charge it.
Apple hasn't drastically improved the Apple Watch's battery life in a while. In my experience, the Series 5 lasts for roughly the same amount of time as the Series 3 and Series 4, so it seems like it may be time for an upgrade.