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.