There are a bunch of little things that would just work on my Android but do not work on iPhone. I already mentioned the web - every browser is just a safari skin. So I can't use my favourite firefox plugins. The YouTube app is not as polished. It won't connect to by cars bluetooth every time and the bluetooth menu takes a lot more taps to access. Siri is really bad it'll often misfire or do the wrong thing. The camera has a shutter sound which is impossible to disable unless I use live photos which take up more space.
The android back button is genius. A stack of views that you pop with a button that is always in the same easy to reach spot. With iPhone sometimes the back link is top left, sometimes top right so I cannot use my muscle memory for navigation.
My gripe with Android is that no one offers the quality and form factor of the iPhone SE. (Though to be fair, even Apple no longer offers the quality and form factor of the iPhone SE...)
I was on Android for years before I switched to iOS. Did the switch largely due to Apple providing updates for longer than the Android devices I owned. Stayed because I found I preferred iOS.