A sad reality, I believe, is that Apple is using the iPhone 8 (6, 6S, 7, 8, call it whatever you want) form factor because of $$$. At this point, the ONLY iPhone being sold with the iPhone 5 form factor is the iPhone SE, and those numbers are dwindling due to a lack of update. Keeping that form factor would be more expensive continuing the iPhone 6 form factor whose manufacturing processes have been scaled and perfected over the past four or five years (however long it's been, sorry). A great way to keep costs low and possibly get rid of extra product such as the front and rear panels is to continue the iPhone 8 form factor.
It's unfortunate. Just my $0.02.