Sharing contact information directly phone to phone.

Lock screen widgets, giving me information at an actual glance without the risk of getting sucked into other random bullshit.

I miss the rooting era before google safety net. I rely on a lot of banking apps and other stuffs that require safetynet. Even though they are tricks to hide root and bootloader status, it is pain in the ass. Fuck I can't do whatever I want on my phone right now. If there was no safetynet my phone will be running pixel experience or lineage os.

Those missing physical buttons to type. Have you used swipe typing? It saves a massive amount of time, not tap tap tap, it's just swype across the screen to the letters and you're good. Very easy and fast.

Apple’s 3D Touch. It was predictable, reliable, and, apparently, under-utilized by the world around me.

There were a couple of phones HTC made (both under their name and rebadged as early Google Pixel phones) that could detect squeezing the phone as a programmable button press. It seems like it'd be clunky and triggering at the wrong time or not triggering reliably when you needed it but it was just really well implemented so it worked perfectly. Slightly increasing how tightly you're holding the phone is such a tiny thing to do so getting a full extra programmable button out of it was actually really useful for making your day to day phone usage slightly smoother and more efficient.

I'm guessing it just didn't get enough use because people aren't likely to try it intuitively.

i really liked the Soli sensor that Google used on the singular phone. I loved waving across my phone to change the track but y'know google and how they be killing everything cool ever :(

I liked the People Hub that Windows Phone 8 started with. But none of the social media platforms wanted you to be able to use their services without seeing their ads so ...

IR blaster in my phone.