Pretty much no phone is directed at everyone else’s face all the time, that alone is the huge difference. It’s the differences between someone using their phone and someone actively holding it upright to record the crowd. Surveillance cameras might be out there too but they aren’t sighted by everyone (different by country, some even have to deleted after 24h, unless there was a crime).
People quickly would tell you to stop recoding, if you’d hold up your phone all the time, even in situations where you’re closer to each other, like in public transport.
Im sure you could find a usb c camera that could easily be obscured or pinned to a lapel or otherwise disguised for cheaper than the price of a pair of smart glasses, or even just wear your phone on a lanyard around your neck with the screen facing your chest. People might think its weird but noone is going to second guess it unless your phone is in your hands actively pointing at them.
