Comparing the battery life of my Pixel 4a to the Pixel 2 back when I made note of it four years ago. Screen on is still at 5 hours, but screen off increased from 36 hours to 45 hours and combined increased from 26 hours to 36 hours. Obvious the combined hours is influenced by the increase in screen off and the screen off reflects the operating system optimizations. Screen on time tells me little has changed in screen power consumption.