That was one very good reason for me to choose a FairPhone. (Almost?) everything is user replaceable. It has been in my pocket for a could of years and I have not needed to replace anything yet. But I do like having the option.

Samsungs Galaxy S21 is also really simple to fix stuff. The back is made of relatively flexible plastic connected via glue, which you can easily get under by blowing into the charging/speaker port. Once your inside its all just a lot of screws.

Had to reattach the battery ribbon cable after my phone fell one too many times (I could have also just fixed it by pressing on the back in the right place, but I only really figured that out after I disassembled the phone).