Well, that can't be strictly true, since no one is born knowing these things, yet people do learn about them. I don't think it's crazy to expect people to desire to read a quick guide or watch a quick video about UI paradigms/tricks/shortcuts for what is likely to be one of the most complex and most frequently used electronic devices in their lives.
I do agree that 3d touch is a bad idea, because there's no pattern to learn other than very specific per-application places it can be used. If there was some visible UI hint that an element was 3d touchable, perhaps I would be more of a fan.
As for the double-click and triple-click stuff, I can't really think of that many examples on iPhone. I believe triple-clicking a physical button can be used to enable accessibility features? I think it's pretty acceptable to have accessibility features that drastically transform the phone's user experience fairly hidden, as long as they're well documented for the people who need them.
Is 'accidental discovery' part of the superiority of Apple's design ethos?
I think it may be that "affordances" are hard on small touch screens. I mean, the "affordance" is that you can touch it, that's about it.
Really, even on desktop, we know how to use it cause we've spent years learning how to use it. The first GUI's had _much_ simpler UX's with many fewer interaction modalities, cause it was hard enough to get people to learn those. (I remember classes on how to use a mouse -- it was not obvious). They got more complicated as generalized "society" learned to use the simple ones.
That’s only true if you’re already accustomed to how Apple does things.
Consider the iPhone a perfect example: 300 different ways to single-click, double-click, triple-click(!), 3D-touch (whatever that is) and use random swiping gestures from all screen directions outside the screen, and different swiping gestures within the screen.
Absolutely madness and probably makes at least 80% of the phone’s functionality completely undiscoverable and inaccessible unless you already know it is there.
How is anyone supposed to know about all that? It breaks every design book’s rules by providing zero affordances. Nothing about this is obvious or intuitive. It’s all 100% learned behavior.
And I say that as an iPhone owner.