So from more than 10 years you are suddenly down at 4, with a little more knowledge about Android you will probably get down to 3 years or less like I said at first.
There are system navigation gestures, they are not only applicable to Google's UI(which in your mind most likely it's the home launcher).
Various Android phones already have gesture based navigation controls and gestures were always a big part of Android.
Google simply implemented some additional navigation gestures into Android P. I don't understand how does that make them copy cats and if that's the logic Apple are copy cats as well.
https://imgur.com/o9SFWyt