Hi @Jason13v8 With Android 12 generally has been increased battery drain initially but the situation tends to improve over time with the AI and updates. your situation seems more severe though. Have you wiped the cache partition lately as that is recommended following updates, deletes temporary files but not data.
You should perform the following procedure to see if that makes a difference:
1. Turn off the device.
2. Connect To Computer or plug in USB-C Headphones , Press and hold the Volume Up key and then press and hold the Power key (plus Bixby Key if phone has one)
3. When the Android logo displays, release all three keys.
4. An 'Installing system update' message will show for 30 - 60 seconds before the Android system recovery menu options appear.
5. Press the Volume down key several times to highlight wipe cache partition.
6. Press Power key to select.
7. Press the Volume down key to highlight yes, them and press the Power key to select.
8. When the wipe cache partition is complete, Reboot system now is highlighted.
9. Press the Power key to restart the device.
You could also repair apps from the same Recovery Menu or run the Galaxy Apps Booster (available from Good Guardians).
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 4.0,Android 12 Official Version.