Soft keyboards have haptic feedback. But that aside, they also have a bunch of accommodations to make up for their inferiority. Dynamically-sized keys, automatic typo correction, Swype.

This project is not a replacement for phone keyboards, and if it was then I would still consider it inferior to physical keyboard in the same way that touch keyboards are inferior to them. Phone keyboard require a lot of hacks to make them more acceptable, from providing haptic feed with vibration to inferring the letter desired through proximity, which it often gets wrong for people with larger fingers.

None of which matters though, because that isn't the use case on display here. The use shown is extremely similar to the projected keyboard to which I linked, which has remained a niche application.

So, my point stands: A use-case other than inferior versions of input devices is needed to demonstrate the value of this innovation. It is an interesting innovation, and my inability to immediately think of commercially viable applications for it doesn't change that. It's great that we come up with novel advances like this, and have them in our massive tool chest to pull them out once we connect the technology to a practical application. All I'm saying here is that, as presented, we don't have that connection to a practical application.