1. First, Taptic user interaction won't be identical to a physical switch, at best it may be adequate but not as good as I'll explain (that's Johnson's point).

2. Both a mechanical push-button switch which actuates (that is, parts move to switch on) and Apple's Taptic switch are BOTH haptic devices/interfaces by definition. Here's part of the Merriam-Webster dictionary definition of 'haptic':

"haptic, adjective

1: relating to or based on the sense of touch

2: characterized by a predilection for the sense of touch

https://www.merriam-webster.com/dictionary/haptic

3. Again, the thrust of Allison Johnson's article is that the more familiar mechanical switch interface works better than an Apple's Taptic capacitive-type. There is no doubt about this as switces without tactile resistance do not provide dynamic feedback to the human who pushes it. It's why so many hate smartphone keyboards—they only use them out of sufferance because there's nothing better. They've a dead feel and are dynamically unresponsive.

Nothing illustrates this better than competative gamers who demand mechanical keyboards. For them, everything about a keyboard is important, its size, rigidity, stability, visual feedback (lit keys etc.) and especially the key switches—all of which contribute to the main haptic feedback (interaction) that the user experiences.

Diehard gamers demand 'Rolls Royce-type' key switches of the highest quality, these are usually made by the industry leader Cherry. Even then that's not enough, they'll select a specific type of key that has acceleration dynamics and actuation pressure to their liking and particular working style. It's why Cherry and other keyboard manufacturers grade their keys by color, red, blue, black, green etc.: https://keebnews.com/mechanical-keyboard-color-switches-guid....

Same goes for the original IBM PC keyboard, anyone who has ever owned one would never part with it (here read, 'It Sounds and Feels Satisfying') : https://www.howtogeek.com/661430/why-i-still-use-a-34-year-o....

4. A well made mechanical switch provides consistent tactile feedback, it offers increasing mechanical resistance up to the point where it switches, moreover, it not only switches cleanly and repeatedly but also has a predictability about its operation. As such, the human has confidence in it and thus it becomes an extension of his/her body (fingers). The more predicable the switch's action the more effective it is as an extension of the human anatomy.

5. All these switch parameters are important because the tips of human fingers are exquisitely sensitive to touch and feel, a human notices even the slightest change in acceleration, pressure and means of touch. 'Taptic' type buttons are made to mimic a mechanical one; that is they can be made to respond to the speed of a user's actions (time rate change of capacitance as a finger approaches/withdraws), and the pressure applied (capacitance changes as the area of the finger on the surface changes—it increases when the user pushes harder as more skin touches the surface). Note: this is a vast subject and I've barely scratched the surface.

No doubt these Taptic-style interfaces work as they are the basis of modern screen operation in smartphones. However, they are far from perfect. I'll illustrate what I mean by example. Above, I moved the order of two sentences about, and as this is comment is being prepared on my smartphone, I selected the text to be moved by highlighting it with my finger. The trouble was (as is so often the case with many others and me) selecting the text this way was difficult, in fact it's often a damn nuisance. Either one's pressure is too high or too low, or the conductivity of one's fingers changes with circumstance or the granularity of selection is wrong—finger too big, text too small, etc.). Irrespective, selecting text on a smartphone is much harder† than with, say, a mouse.

The fact is that whilst these Taptic-style interfaces work they do not provide the dynamic tactile feedback that a proper mechanical switch, mouse, joystick or stylus does (the stylus is why I loved my old Samsung note3). Simply, the dynamic tactile feedback is missing. A crude analogy would be the withdrawl method of contraception—works sort of but not very satisfying. The fact is human body requires this subtle feedback if it's to work at its best. Another good example is a pianist and the feedback from piano keys. When a pianist tries to play an organ, harmonium or an on/off electric keyboard without dynamics for the first time then he/she is often thrown completely, the result is often horrible.

There's no doubt that Apple's engineers will go to inordinate lengths and use combinations of algorithms to optimize the Taptic performance and no doubt it will work but the fact still remains that without tactile feedback that possesses dynamic range—as opposed to a finger hitting a glass or other hard surface—then effectively the tool/human (haptic) interface is only half done. QED!

6. You wanted a finely-ground answer and now you have one. My argument was and still is that whilst the author's choice of words could have been better in that her usage of the word 'haptic' is loose to say the least the thrust of her point/argument is nevertheless crystal clear. I still can't understand why you cannot see this. Essentially, with your understanding of ergonomics (and presumably haptics) you should have skipped the somewhat mangled terminology and cut through to the core of Johnson's argument.

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† For those who would question otherwise I'd ask them to check the size of the text compared to their finger size. Often this is suboptimal, especially so if one has large fingers and one chooses small text as I do (for me, the more text per screen the better).

This type of limitation/problem is not a function of brand or O/S (Apple versus Android) but rather it's intrinsic to its modus operandi for reasons stated above. That said, the quality of the implementation differs between brands/systems but the fundamental design limitation remains.

Whilst I'm not doing so here, I often use a Bluetooth mouse and keyboard with my smartphone as this overcomes these limitations—I even get to choose the type of keys on my mechanical keyboard. The fact that PC peripherals can be used with a smartphone is clearly a tacit acknowledgment by the designers of the limitations I've been discussing.