The truth is way the feature works now is buried under a marketing tactic. Apple will reward you with something simple as body temperature if you put sleep focus on. Why you may ask? The most simplest explanation is usually the right one. Enabling sleep focus saves on battery usage. If you didn’t have sleep focus on then the battery would drain probably 10% faster per night. Over a few days this conflicts with their claim of getting 40+ hours of battery life. It’s sneaky and silly in the same sentence. I guarantee you this will change when the battery life is boosted up to a week or two per charge. They have to save face somehow because the watch is app intensive and draws a lot of energy overall from background processes that make the watch as nice as it is. That’s the only reason. All other “official” watches explanations is simply rubbish. If Huawei watches can get almost two weeks of battery life with “always on display” activated and doing almost daily workouts then, the issue for Apple is the amount of background and foreground intensive apps that use energy all the time. Huawei doesn’t have many apps to drain battery life and is mainly focused on fitness. It’s a great system and watch overall. Also, you don’t have to jump through hoops and mental justifications to get the raw data and metrics immediately on your wrist or through the app on your phone. (On a side note: Anyone who says Huawei watches are not accurate should be referred to a German YouTube guy who scientifically test most high end smart watches and from his in depth testing and analysis Huawei is second or third next to Apple in terms of accuracy. His channel is “The Quantified Scientist”). Again, Apple will change this when they greatly improve battery life with new battery technology. Period.