iPhone 6 is surprising indeed, because upcoming iOS 13 does not support it. Selling devices which will stop updating in a few months sounds very bad.
[1] https://singjupost.com/tim-cook-at-apple-wwdc-2018-keynote-f...
This trend honestly makes me feel dirty to work in software. If you only use a few core apps, iOS 12 looks and feels just like iOS 7, yet it needs several times the horsepower to work. And unlike on the web, we can't blame it on JavaScript ads. It's just shoddy engineering that aligns with Apple's incentives.