[jpm_sd]

Google put a ton of R&D effort into gesture sensing with short range radar (Soli) but it doesn't seem to have gone much of anywhere as yet. I don't think this type of interface is as important as the author claims.

https://atap.google.com/soli/

[valine]

Google's gesture sensing went nowhere because it was laughably bad. It routinely failed to recognize gestures, was poorly integrated into the OS, and couldn't even be sold in several countries because of its use of radar.

[judge2020]

It was such a gimmick on the Pixel 4, probably because it required you position your hand over your phone. However, if you can just make the gesture of turning a knob regardless of your hand position (which a wearable probably could do), that seems like it'd have a use case.