I have an iPhone 11 Pro. Had a worn down battery until a month ago.
That is really a reason for upgrading. Four year old phone which frequently does not get through the day without a recharge.
I did not upgrade. The camera bump on the current models made me not upgrading. I just do not like the camera bump. Looks ugly. Feels strange. I want the phone flat on a table.
I did a battery swap on the 11 Pro. That should do for another two years. Lets see what are the options by then.