Android 12‘s most noticeable feature is the new “Material You” UI with system-wide color theming. Simply change your wallpaper, and the phone’s UI matches the colors. A smartphone OS of yesteryear had a similar idea years ago, and it was great.
You might remember Microsoft’s last attempt at a smartphone OS, Windows Phone. It was ahead of its time in many ways, but ultimately, lack of app support was its biggest downfall. However, one thing that Windows Phone absolutely nailed was its “Metro UI” design.