I would just like to share here an example of the difference between modern haptic feedback and traditional rumble. Mind you, that video was recorded 5 years ago and is already referring to an old device.
Haptic feedback is not just the rumble that console controllers use nowadays (yes, including the Switch HD rumble - which Nintendo never even marketed as haptics), nor just the adaptive triggers - which the DS is indeed copying from the X1 controller.
Haptic feedback such as the one provided by the Steam controller (which is what I believe Sony copied) can provide a wide range of subtle vibrations.
Technically, haptic feedback just means some kind of stimulation that emulates a sense of touch or feeling, so even the old rumble actuators are providing haptic feedback.
The Switch and the Steam controller are both using linear actuators, which can vibrate and stop much more quickly and at much higher frequencies, to the point that both can actually act as speakers. The difference is that the Steam controller's vibration is being mostly directed to the thumbpads. It is the same tech though.
The "HD Rumble" being able to react so much more quickly/accurately on the Switch is also why lockpicking is broken *in Skyrim. On the old rumble actuators you woukd have gotten a nudge when you got the stick at the correct angle if you were going slowly enough. On the Switch, you can open just about any chest without putting points in because you get a quick click exactly where the sticking point is.
The simulation of friction on the Steam pad doesn't really work out the way he describes it in my experience. It's more often used to help you track the movement of your thumb across the pad, and it feels like... popping micro bubble-wrap, or maybe wiping shaving cream off if a hard surface. You feel a series of pops, like tiny bubbles, but I've never felt it vibrate fast enough to make the pad feel more or less slippery.
I have no doubt that Sony will also be using linear actuators/HD rumble like the Switch and the Steam controller. It sounds like they may even be directing it at the sticks somehow, which would be closer to the Steam controller's implementation and could create some interesting effects.
The question is, are they also using ANOTHER form of haptic feedback to give additional sensations not possible with linear actuators alone. Some rumors have described actual resistance being added to the triggers (and possibly the sticks) to simulate pull. This would be an all-new form of haptic feedback, similar to something described in a Nintendo patent, but never used in any controller that I've seen.
If it is just linear actuators we're talking about in the PS5 (though likely more/more powerful ones) then I'll be pretty disappointed after hearing all this talk about feeling the tension of the bow string. Having Steam controller-like creaking when you pull the trigger to draw the string would be a nice effect, but not the revolution I was hoping for.
*Edited the bit about lockpicking for clarity.
