I think it's also a chicken-or-egg question:
Apple users are more willing to pay for apps. So if you're a dev and you want to release a paid app, iOS is the platform of choice. So more devs release paid apps on iOS, so iOS becomes the platform with more paid apps. So users are more used to pay for apps. So paying for apps is normalized, so Apple users are more willing to pay for apps.
Etc. etc. etc.
It's not so much that iOS is confusing.
It's more that you have to learn which things are just completely impossible to do on iOS for the single reason that Apple doesn't want users to do those things.
On Android, things that should be possible from a technical point of view are generally possible. Might take a while to figure things out, but generally, things are achievable.
On iOS, there's either a fairly straightforward way to do things, or there's not even a point in trying, because Apple has locked that shit down to the point where you'll just waste days trying to find a way, only to give up on the end.
I've got endless examples, from trying to move files/documents/music on, to, or from an iOS device in a non-Apple-approved way to sending media over non-Apple-approved channels to something as simple as syncing calendars in a way that Apple doesn't like.
On Android, all of these things can be achieved in a couple of minutes.
I used to bother with jailbreaking and all that jazz - but ultimately, to me, owning a shiny Apple device isn't worth having to deal with all the randomly imposed limitations.