Hi @vicky40 I agree with the points @Maria_vm and the A12 would certainly be a downgrade compared to the S9 in terms of display and processing speed as well as the camera quality. You can see some comparisons here https://www.phonearena.com/phones/compare/Samsung-Galaxy-S9,Samsung-Galaxy-A12/phones/10716,11552
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.