Upgraded from S9 to S21 primarily for the camera and hopefully a better battery life than what I was getting on the 9. So far its good, wouldn't say better than the S9, at least the same. The battery does seem to last longer but haven't had it long enough to give it a good shakedown. One thing I do NOT like is that after the screen goes dark due to inactivity you have to depress the on button on the side to bring the screen back up. The S9 you just swiped up the screen and that is my main reason for the 3 stars, not higher. When you are driving, having to push the side button means taking it out of the holder and I think everyone would agree that does not lend to safety while driving.
I love everything about this phone except the battery life. I upgraded because my old S8+ was losing charge so quickly. I know other phones have much longer battery life and believe Samsung could do the same. Disappointed in that but everything else is great.