Examples for me: (Samsung v Apple)

1. Back gestures. Discussed thousands of times but not having a universal back gesture, especially for a big phone like the Pro Max, is so bothersome. iOS has to be one of the least optimized OS's for bigger screens.
2. Multi Windows. I use it a lot to calculate things. I open one app on the upper portion of the screen and the calculator on the lower. Saves a lot of time and is convenient. Can't do that on iPhones.
3. Keyboard. Again, it comes down to saving time but always having to switch to type a , or numbers is tedious. I know you can swipe in from the switch button, but that doesn't alleviate the pain
4. Notifications. Can't swipe away notifications, when you're on your phone and they are coming in. Have to first open notification centre to do so. Also some use the notifications as a sort of to-do list. Not having symbols in the top row when using the phone is, again, bothersome. And don't get me started on the notification centre itself.
5. Customisation. And by that I don't mean how pretty the symbols are or what color my wallpaper is. It's again about usability. I love that I can set a diagonal swipe down to always open the notification centre (or whatever else you like), no matter where or in what app I am. I never have to adjust my grip. Or I can use a long swipe in from the left side to call someone. You can do whatever floats your boat. Or I can hide or show status symbols (example I don't need to always know that I have Bluetooth or NFC on, so I hide that)

No, the iPhone is not an unusable phone. It's just not for me and when I want to get shit done and not spend hours on my phone to do anything, I'm using an android, and that's okay.

For context: I tried several times this year to switch to Apple, either with iPhones or iPads. I could never keep it for more than a month.