Clean internal layout, relatively serviceable, structured light 3D scanning built in. You can debate whether or not Apple have made good UI decisions, but the hardware design execution here is superb.
Check out all their in-depth guides.
Props to the Fairphone 2 for receiving a 10/10 for repairability.
Their service is pretty good too by the way. I had a broken bottom module and when I contacted them was sent a new one the same day. Took a week to get here because international shipping but that's hardly their fault. Repairs really was just power down, open phone, unscrew component, put in new one, fasten screws, boot up phone. Took me fifteen minutes, which felt awesome.
I'm not going to deny that the newest iPhone is both more advanced technology wide and just gorgeously designed, but in all honesty, smartphones hit a level of "good enough" a few years ago and it will take quite a fundamental leap in features for me to really want and upgrade.
The only issue is that the camera in this thing is still frustratingly sluggish to the point where it feels like a downgrade compared to my iPhone 5s. Maybe the software is partially to blame, I've been looking on fdroid for replacement apps but none seem faster.
I hope they sell a shedload, Purism also.
I will admit that the iPhone is a good phone though!
Then I realize, the only reason this is remotely possible is due to volume. So it almost says less about technical progress and performance per cubic inch per dollar coming down, and more about how volume makes the above possible.
Though most impressive ever for me was a Panasonic cassette player (walkman style) in the 90's. The thing was barely larger than a cassette itself. My young mind was blown out.