There’s a gesture for it now, too... but I have no idea what it is. Something like swiping three or four fingers down or across or diagonally. Definitely not discoverable.
This was replaced in iOS 13 by a less comical, yet equally undiscoverable three-finger tap gesture.
Considering that command-Z is not discoverable either, it’s not too bad, especially as there are undo/redo/clipboard buttons on the keyboard in most cases.
