I am an equal opportunity hater. iPhone and Android both suck.
That said, iPhone sucks less IMO. I just want the thing to be a phone. I don't want to have to perform rocket surgery to use it. I can find my way around an iPhone with my eyes closed. (Used to be able to do it with one hand tied behind my back, too, but then they quit making them in my size, so I have to use both hands all the time)
As a user, I find Android to be less intuitive and more cognitive load to do the same tasks, especially when changing between many Android phones (Samsung, Google, etc.) due to the different skins. I have to do this though because of testing Android apps on a few different phones.
From the perspective of an accessory developer, iPhone wins hands down. There's no equal to the Apple accessory interface and the ecosystem of things built around it. They're getting USB-C now but there are still interfaces available on an Apple device that aren't available anywhere else. Rich playback controls, music database and now playing track info (for head units), reliable communication with apps, to name a few. Android Open Accessory protocol is the closest there is on the other side, but it doesn't check many boxes, and it's hit or miss whether the phone even supports the few things that it does do.
In the operating system developer department, fack Android, seriously. AOSP is a witch with a capital B to build and customize, and it is nigh impossible to find replacements for the closed-source Google applications that many people think of when they think Android. (Assistant, Maps, Android Auto, Play Store, Play Services, etc., all those things are not open and Google doesn't like to give access to those things to smaller developers--especially if you plan on making a truly open "developer mode" device)