Apple needs to have a middle ground Pro phone and believe that was actually the 5.8 iPhone X.
Even though I still thing its heavy, its still manageable; especially for one handed use.
This is what the iPhone lineup needs to look like:
iPhone SE - Touch ID phone - no frills iPhone, the cheapest at 299, easy to get super cheap discounts that can bring it down to 180. If you are an iPhone Pro Max user and you are concerning yourself with the 4.7 inch screen, I would just tell you to mine your own business. Its not for you. Its for people who just want a solid, well tested phone that works just like how their iPhone 6 from 2014 did. It has the latest SOC so it gets the latest updates. Its also great for businesses such as hospitals that want to purchase a cheap iPhone in bulk for nurses, doctors, staff and patient bed side phone. If one goes missing, its not a huge cost either.
iPhone and iPhone Pro - 5.8 inch screen - this is the for the standard phone for those who want a little bit more and if you need capabilities of the Pro Max in a manageable size, this is it. 699/999
iPhone Plus and Pro Max - 6.8 inch screen - You are basically using this to shoot RAW photos, low budget TV show, YouTuber and basically need an iPad Mini on the go. 799/1099
Last years standard model takes the 599 spot
The model year before that takes the 499 spot.