IME it's the exact opposite. That iOS undo action is more or less theoretical - the apps that support that are some of Apples... And that's it.

The android back action is universally supported. Its literally a button, still, to this day, persistent on your screen by the OS.

Also, the "swipe back" action on iOS is more or less fake. Its applied so inconsistently it might as well not exist.

In my head "back" and "undo" are usually the same thing. iOS has a good interface, but this is one glaring blind spot they missed to Android and browsers. It actually makes iOS quiet frustrating to use.

Also, barely related: but the "shaking your device is like shaking your head no" thing is the stupidest thing I've ever heard in my life. I'm sure Apple thinks its very intuitive and good design, but it's really, really not. That's one of the least discoverable things I've ever heard. Apple please don't do that.

Swipe to go back support is pretty wide if you select for iOS-first apps (I do). It’s glaring when I try to use it and it’s not there, so when that happens I’ll either go find an alternative or drop back to the web app (where Safari will definitely implement it).

My Android devices all have the gesture bar enabled because the old style button bar is an eyesore and easy to trigger accidentally (Android’s swiping from the right to go back is also too easy to trigger as a right-handed person, but that’s another story).

My metal model for the undo/back split actually follows desktop browsers. Cmd-Z isn’t going to undo navigation while Cmd-[ will, and so the two are separate and distinct.