I have an SE 1 - recently replaced with a 12mini.
The SE1 model is 7 years old and is nearing end of life; mine had a lousy battery life, quite a few apps wouldn't update anymore (including BBC apps) and it was getting quite slow.
Clincher for me was dropping it and busting the screen
Looked at SE 2 and 3 but both significantly bigger than the original. In the end I settled on the 12mini - only slightly larger but retains the squared off edge. Good price too.
Tech changes are a bit frustrating but getting used to it. Camera is better.