On my old phone I had an issue with the proximity sensor and front facing camera. This led me to holding my phone backwards to take photos and being unable to hang up phone calls.
I think I put up with this for a year and a half.
I did end up figuring out the issue with the proximity sensor but opening up my phone to reconnect the camera module was too much effort for me.
My 6s still works. I did have the battery replaced 3 years ago because I expected to continue to use it a couple more years. I got a new phone last year but my old one is still happily running.
It belongs in a museum!