Ah man, I thought you were going to go nuts in this segment.
Maybe you needed to specify a timeframe. 5 years? 50? 100?
I’ll rattle a few off for ya.
Safety: Any phone thrown up into the air (forcefully) immediately activates a drone mode where phone tracks and follows user while simultaneously broadcasting video/data to preset contacts.
Phone integrated into body. Black mirror level tech. Archangel etc.
Taser mode… (lol)
Display: Wall projectors, vertical hologram out of phone, In eye display (I know you mentioned that) organic body display aka On your palm or inside wrist.
Battery: Unlimited. How? Don’t know. Maybe a new kind of dedicated grid to power ultra low power devices. Just saying, this would be a huge upgrade for mobile tech. Old phones would be obsolete overnight.
Durability: Indestructible. Straight up unbreakable.
100+ years: Basically ghost in the shell. Assuming everyone has the minimum communications tech, everything else is just a buffet of upgrades, there is no ‘phone’ just a vast array of the features that phones used to have, separated out and installed as desired.
AI: aka ‘Her’ everyone has their own personal AI secretary. Everything done through AI hologram, natural conversation and 3D holographic display, phone (or chip) is just for taking AI with you. aka Blade Runner 2049. Maybe only you can see it - legit personal.
Could prob think of way more, depends how far forward you want to go.
I think unlimited battery and indestructible would do it for most people.
Edit: Oh god the entire medical industry moving into phones. Emergency drug synthesis, real time medical diagnosis etc