Different strokes for different folks but I wouldn’t want a voice-controlled “smart” brooch if it was free and worked flawlessly.
It also seems like it should be a Bluetooth phone accessory that cost $99 or whatever. I wear a smartwatch so still not for me but maybe if they made it stylish (or just less conspicuous and geeky), it could fill a gap in the market? Some of my friends wear traditional fashion watches, bracelets, etc. and usually leave their phone in their purse. They might like the form factor as a way to stay minimally connected in case the baby sitter calls or whatever.