The main reason I personally don't like iOS is because Apple heavily locks down what you can and can't do with it. With iOS, you can't download files through Safari. Moving files around is more difficult than it should be. The built-in file manager app on iOS is rudimentary compared to what a file manager on Android can do. When I used to use an iPhone, I would have to use iTunes on the PC to copy my music over. However, on my Android phones, I can just drag and drop my music files without any other software. Hell, I can even plug in a USB-C flash drive to my Galaxy Note 8 and copy files very easily. Apple won't let you do that.
If Apple would make their iOS a bit more "free" in the sense of allowing more customization options, better file management, etc, then it might convince me to switch over. Until then, I'll prefer Android.
Another thing that I find amusing is that Apple (I'm not sure if they still do) would always tout the iPad as being a desktop/laptop replacement. However, iOS doesn't have any mouse support (maybe in iOS 13?). The touch interface is great for somethings, but sometimes having a mouse is beneficial. And same thing with the whole file management issue. If an iPad is going to be a computer "killer", then I'd expect it to be able to easily copy files through a flash drive and not rely on cloud services or having to use iTunes to move stuff around.