I cannot speak for Android, not being a regular user, but I have never, ever seen a first-party on iOS get its own UI stuck. It may crash rarely, but it will never get itself into a state where the user is powerless to do anything with it (short of killing it).
Most iOS users I've met aren't aware of the kill-app functionality, and they don't need to, because first-party apps don't have egregious enough bugs like "button to return to main menu reacts but does nothing".