I think iPhones are among the easiest to fix, nothing is sealed no mess no glue. The cheap replacement screen for 5,6,7 cost around 20£ and takes around 20min to replace.

should have known this, since it seems like common sense in retrospect.

I'm projecting from impressions I'd made since the Mac book pro became harder and harder to modify and upgrade. I'd constructed a faulty assumption about the repairability of iPhones.

It's never been difficult for me to find someone to repair one of my old iPhones in the past, I just quit on iPhones last year and feel somewhat disappointed with them since the v7s. (I am a fairly recent switcher to Android.)