If you're coming from a 6S or 7 it makes no sense to pay full price for pretty much the same thing.
Your statement Is Rather bleak . The iPhone 6s and iPhone 8 have quite a few differences with the camera, display improvements, water resistance rating, wireless charging, stereo speakers, battery life, etc. I would say it's a fairly decent upgrade for those coming from a 6s to the iPhone 8, but from the iPhone 7 to the iPhone 8 would be more Comparable.