Received ONE UI 7 update in my S21 FE today. NOT Happy at all. The update ruined many default settings (like black BG during calls and brought bright BG), showing just signal bars and NO VoLTE/Vo5G/LTE/4G/5G/3G/No NW sign when connected to WiFi, LOTs of lag in UI - so much so that I have to check if Animation scale was increased in Developer Options (which is still OFF now).
After One UI 7, S24 series UI Speed is improved a lot,
S23 series UI Speed is as good as before,
S22 series UI Speed is slightly lagging, but NOT drastic (as seen in my wife's S22+),
S21 series UI Speed is lagging too much. Even my Exynos A55 is faster now.
Can you notice the Pattern here? It is "Planned obsolescence". Samsung is forcing users with old phones to go for new phones. Their effort will get 50% success rate for sure. That is People will buy a new phone (50% accomplishment), but NOT from Samsung (balance 50%).