[Someone1234]

It was a hidden feature that Apple struggled to communicate (and was hard to describe without physically trying it) was always going to be problematic.

How do you train users? What is the discoverability? It was a legitimate problem when most of your user-base aren't tech nerds and most people aren't reading the manual/help guides.

So you implement an app feature via 3D Touch and users just assume that feature doesn't exist (because they don't discover it). Then you add it twice (3D Touch AND non-3D Touch) and you're now maintaining two things, and have gained little to nothing via 3D Touch.

I liken it to Windows 8's gesture UI failure. If users cannot discover it, it doesn't exist. So you cannot really build much around it because you have to assume user ignorance.

[vbezhenar]

How do you train users about mouse right button?

[tpmx]

By implementing it at the beginning of a UX paradigm cycle when the numbers of users are small, curious and in learning mode. Like how right-clicking was introduced when the number of Windows users was like 1/1000 of the number of the peak number of Windows users.

You don't implement it during/after peaking of said cycle. That's some crazy level of delusion/arrogance. Turns out not even Apple can do pull that stunt.

[macintux]

And I’d wager a significant percentage of Windows users still don’t use it (or don’t understand when to use it).

And it’s vastly more discoverable than 3D Touch.

[Someone1234]

with a huge amount of difficulty?

Most computer users still don't use middle-click/scroll wheel click, or even the back/forward buttons and they're almost twenty years old.

By simply pointing at another hard to train piece of hidden functionality and saying "what about THIS?!" you haven't really proven anything, except that with enough forced training anything can become common knowledge.

3D Touch is exactly like right click, but they're also competing against implicit training via passed users of Apple's own products, other touch devices, and even other computing (since no other platform has anything like 3D Touch).

They offered no on-screen guide or tutorial when it launched.