It's because many iPhone users started on Android and switched to iOS 5+ years ago when Android was still unpolished, glitchy garbage.
I was one of them, but I recently tried a Google Pixel 4A for a few days and was extremely impressed with it and how far Android has come. Android is a lot more polished than it used to be.
That said, "easier to use"? I can't say I agree, especially with Samsung phones. I find Android to be a bit cumbersome to use compared to iOS. I think it probably comes down to which one you're more used to.
I'm in this category. My first smartphone was the HTC Incredible. I eventually switched to an iPhone 6S Plus because I just wanted a phone for its simplicity (compared to Android phones at the time), and I never went back. Most of my issues I had with Android phones don't exist anymore, but I don't have any interest in going back. It has nothing to do with Android phones; it's just that upgrading to a new iPhone is easier. Here are some of the reasons why I made the initial switch:
- I was getting overwhelmed with all of the gimmicks and gestures. Swiping with one finger to bring this up, but swiping with two fingers to bring this other thing up. Tap with your knuckle to do this, but tap with your finger to do that. Swipe on the top right edge of the screen to bring up this drawer, but swipe at the bottom right edge of the screen to bring up this other drawer.
- It bugged me that the application icons were different sizes and shapes. I thought it made the homescreen and app drawers so ugly to look at because everything looked so random.
- I didn't like how there were two of each application, depending on which phone I purchased. (Google calendar and a Samsung calendar. Google mail or HTC mail.)
- (This is more on Google) I didn't like how Google would create these new apps and then abandon them.
I'm the first to agree that these are nit-picky. And, again, the majority of these issues have all been addressed, but these were my annoyances at the time of my switch. It never bothered me that I got updates late or I didn't have any support. My issues were more cosmetic.
Currently, one thing that I love about iPhones (and iPads) is that I'm able to help my parents whenever they run into a problem with their devices. My parents are senior citizens and first generation. Regardless of which language their phone is in, my menu will be in the same order as their menu, so I can walk them through anything. I can't do that with Android.