There's not really something that would be 'revolutionary'. However, I think there are some things that could 'wow' users:
- A new design (really new, because the current one is basically an iPhone 12. Something like going from a 3GS to 4)
Okay… now elaborate.
There were extremely obvious improvements that could’ve been made between the design of the 3GS and the four.
The 3G/3GS we’re both thicker than the original iPhone, built with a much less durable and easily discolored plastic, and had a curved design that reduced space for internal components.
The 4 just fixed all of those flaws. No more cracking around the charging cord, because the sides were made of metal. A flat designed to maximize space for components and battery. A glass back.
These days we are still using the metal frames, the glass backs are pretty much required because of wireless charging, and with how the cameras are these days, you can’t really make the phones any thinner than between 6 and 9 MM.
- Display tech: maybe 'directed HDR'? Imagine having a photo where you look at some water and than when you tilt your head, the way the sun reflects the water also changes. I'm not talking about a software effect here. I'm talking about just moving your head around and you seeing different parts of the image from a different perspective, like in real life.
- A breakthrough in battery life. Like instead of you charging your phone each night, you'll need to charge it only like once every few weeks.
The 3D display in a phone has been tried so many times and failed every time.
The most successful attempt was probably the 2014 Amazon Fire Phone, which used four different front facing cameras to provide an experience of different perspectives on the UI.
It was praised for being unique in reviews, but in practice a lot of people complained about motion sickness, plus having four cameras engaged at all times wasn’t really practical for battery life.
The other two attempts at 3-D/multiple perspective phones were the RED Hydrogen phone in 2014 and the 2011 HTC Evo3D, both which were complete failures.
As for a battery that lasts for weeks, I think you’ll be waiting a long time for those major battery improvements. Phones have been developed in such a way where most of the flagships get people through the day, and that seems to be what most customers are OK with.
