I agree, but many actions are destructive of previous context. And context is king if you are trying to simplify an interface and still have it intelligible.
So I think what people often want is a generic ‘go back’ command — ie ‘whatever just happened, undo that’.
That’s an interesting train of thought. I’d interpret what you’re saying as “Rewind” more than “Undo” because many actions in iOS aren’t discrete in the ways that we think of with Undo. A proper Undo command on the Mac should always say what you’re undoing, and if it can’t, which I’d argue is near impossible in iOS, there’s almost no point in having it.
But the concept of a rewind that would reset to some previous state (when you last entered the app, for instance) might be more what you’re looking for. Of course, such a rewind could be destructive too, or might not make sense in many contexts. If you go into Mail and write and send a message, rewind wouldn’t be able to bring back the message from the Internet.
Sounds a bit like the behavior of the hardware “back” button that Android phones usually have. Tapping it moves you “back” one screen, whether it is to another screen in the same app or to a different app (e.g. from a web browser to the e-mail message that you tapped on to launch it).
Android seems to remember many levels of this, allowing you to to back through multiple apps until ultimately arriving at the main app-launcher screen.
Apple sort of has this, but it only goes back one level. If one app launches another, you get a “previous app” link in the upper-left corner of the screen, but if you tap it, the previous app doesn’t have a similar link to the app that launched it.
This can be annoying sometimes. Many times, if you tap on an ad banner in an app, it links to a web page that in turn redirects to an App Store page. The previous-app link takes you back to your web browser, but you need to use the app switcher (or return to the home screen) in order to go all the way back to the app you started from.