Whether you have to move your muscles isn't so important, the goal here is to create a control surface that is usable in VR/AR, which this technology can totally still do.
Walking down the street with AR glasses right now sucks because you can't actually do anything without disruptive gestures (holding your hand to your face, talking out loud to nobody, etc). If you could tell the glasses what to do simply by making small imperceptible movements in your hand, that's a huge leap forward towards making AR actually something usable
Even if it was equally expressive, it's probably far less obtrusive to wear a bracelet than wear a glove (though that depends on the design of the bracelet I guess)
Walking down the street with AR glasses right now sucks because you can't actually do anything without disruptive gestures (holding your hand to your face, talking out loud to nobody, etc). If you could tell the glasses what to do simply by making small imperceptible movements in your hand, that's a huge leap forward towards making AR actually something usable