Saw this alternate entry device announced at CES:
SelfieType, using a camera to watch your fingers, looks even more futuristic:
https://www.androidauthority.com/samsung-selfie-type-demo-vi...
Isn't the latter basically just a projection keyboard?
https://en.wikipedia.org/wiki/Projection_keyboard
So, futuristic from the 90s, was available already and flopped (because it is much more uncomfortable than actual keys).
Worse physical feedback than the terminal keyboard made of stones at HEU (Hacking at the End of the Universe) '93. Because there is no physical feedback at all. However, if that can somehow be emulated (like on an Apple Magic Trackpad), perhaps?
You could go for audio feedback at least? https://github.com/zevv/bucklespring