That's a very good and interesting insight. I'm currently posting from my Galaxy S8+. I've been using Android for several months now and I've gotten very used to either the app switching "button" or the back "button" getting me out of poor app navigation interfaces or pop up ads that get past my ad block and hijack my browsing session.An interesting thought for those that don't understand how people get scammed by this - what is the "get out of this screen button" in iOS? The home button. Now, what is the "I want to purchase this" gesture? There you go, trying to not purchase a thing and you accidentally purchase it (And maybe don't even know because they left the app)
That combined with in-app subscriptions being buried in the users iTunes settings means a lot of people not knowing how to cancel.
Additionally, on the Samsung at least, payment authentication methods are separate from navigational controls. In my experience so far it's quite difficult to accidentally purchase something on my Android phone. (On the other hand, in app ads on an Android can be extremely obnoxious to the point of acting like a virus infestation. I have mercifully been spared that but my husband got an app like that once.)
I think Apple should consider incorporating additional navigation keys separate from authentication buttons/sensors in future editions of iOS.
I know Steve Jobs was enamored of a one button suits all purposes design. But such simplicity is increasingly becoming stifling when people grow used to having options or find themselves in situations in which they need options.