An entirely gesture based UI, where even going back to the home screen or switching apps requires gestures, rather than pressing a virtual or physical button. It's the only phone out of all the new "almost-bezel-free" crop that actually makes an effort to get rid of useless UI chrome so that the entire screen is about the content and what you can do with it. And those gestures are particularly well thought. Where the competition like the Samsung Galaxy series removed physical buttons but merely replaced them with virtual ones, you can see Apple going forward, not just mimicking the past, whenever there's a technological progress, like the ability to produce almost bezel-free phones.

Making the bet that people are ready to pay a lot more just for the sake of having something that feels nicer to use is also what makes the iPhone X a bold step, although some of the techs existed in different forms in the previous iPhones. Yes, I'm using the word 'feels' here, it's about things like FaceID, 3D Touch, Taptic Engine and all the other things that make the iPhone X experience radically different to using something like the android competition. They actually had to completely redevelop 3D Touch for the iPhone X, the old 3D Touch technology depended on the LCD backlights which aren't a thing with OLED.

They're things that don't dramatically improve productivity and they're not things that can be considered major features like having a better camera (like the Google Pixel 2 marketing). They're things whose sole purpose of existence is to make interacting with the device feel nicer. It's something that does not exist in android land.

It's that sort of thing that makes me keep using Apple's laptops too, despite the many things I do not like about them (like the all USB-C ports). The Taptic Engine + Force Touch, oversized trackpad makes doing things like dragging something across the screen with only one finger feel so much better than what you have to do with other trackpads which require either pressing the trackpad itself on the bottom area or pressing a button. I'm still amazed they managed to make vibrations feel like you clicked a physical button.