One problem is that Apple doesn't really play fair. If people can't figure out how to uninstall Apple apps, then they probably can't figure out how to use anything besides what Apple gives them, even if you install it for your parents. Like how would your parents ever figure out how to use Google maps instead of Apple maps?OK, if you don’t mind having to help your parents install some basic apps on their new smartphone.
Apple tries to lock its users in when it has the opportunity, and that's often anti-competitive. Chrome on iOS is basically webkit.
And Apple is not just creating phones and phone software and computers and computer software. They're buying up everyone around them and shutting down plenty of other players.
So your parents might not have the easiest time right out of the box, but it might be a bit of an issue when their will isn't valid unless it's certified by Tim Cook and his cronies.