Uninstalling watch faces, no. Just makes it look less cluttered. Uninstalling all the unneccessary apps that are forcible ran in the background and cannot turn battery optimizations or disable backround activities.. It actually does, im fairly sure i gained a hour or 2. Which is a lot with this watch. I dont need world clock or compass to be actively ran 247 without possibility to turn off... Or a damn bitmoji watchfaceits pointles because battery life and performance doesnt change at all