not a good trade but if you are desperate S21 FE would be much better option.

I never thought I’d type this about an Apple product but if there isn’t anything wrong with your iPhone 13, its going to be better in terms of camera and processor in comparison to the midrange A54. Not to say the A54 is bad but the iPhone 13 is a flagship with flagship specs

The only thing you will notice is the performance difference. I’m not saying that the A54’s performance is bad, but A54 is a different tier smartphone