A number of things don't work, or work in unexpected ways, mostly because Apple doesn't allow me to log in to iCloud with such an old phone.

I can't control lights with the Home app. But Airplay works fine. The phone doesn't know what a HomePod is, but it shows up with a regular generic speaker icon, like the AirMac I have hooked up to my stereo.

Sometimes I have a few minutes to kill, and I pick it up to look at HN. The New York Times web site starts to work, but the login page doesn't load at all. WSJ blocks me at a "verifying the device" screen. WaPo half works. eBay works some, but no pictures. Ditto for Wikipedia.

There's a lot of things you take for granted on a new phone that you only realize when you're using an old phone. Like you didn't used to be able to quickly scroll an entire web page it's only a screen at a time in iOS 10. You can't grab the scroll bar on the side and move it, either.

And 99.9999% of people don't realize the genius of the camera island. It makes it so much easier to pick up the phone if one end is elevated a bit. With a completely flat phone, you end up dragging/scraping it along the table in order to grip it, which scuffs the surface. And if the table is really smooth, it's surprisingly difficult to lift the phone straight up.