It used to be better when Material Design came out. It was more rectangular, looked better. Take a look at Android 10. It was much more "expressive". Now, it's just round, as if they're trying to copy the trend set by Apple.

I updated my Galaxy S21 to Android 15 and I hate it. The new design occupies TOO MUCH space, I could check almost all my notifications (I only have 3-4 apps that send me notifications) with a quick scroll from the top, but now a single notification occupies like 1/5th of the screen, making it much more difficult to take a look at all my notifications at once.

The other stupid thing, they moved the media playback to the quick settings panel and made it a tiny widget on the lock screen, on the bottom, where you barely pay attention to it. I removed this widget thinking it would restore the old functionality, but I was wrong. Now, whenever I listen to music, I cannot control playback from the notifications panel or the lock screen, I must manually open Spotify and control it from there.

I don't know what drugs UX designers are on but I can safely say this is not convenient for the user and we didn't ask for it.