There are three main ways to make a smartwatch last longer than a day. Fitness watches with weeks-long battery life have the easiest method: use a wimpy, efficient CPU that sticks to health data and notifications. The other two solutions for longer smartwatch battery life come with drawbacks and compromises, and I'm not sure that'll ever change.
Smartwatch makers know we're sick of recharging our watches daily. They've sped up charging times in recent years so you can top them off quickly before or after bed, making it easier to sleep with a watch. For many, that stopgap measure isn't enough, and they switch to "dumber" watches from Garmin or Fitbit to avoid the hassle.
