cunnililgus

Well, bluetooth, wifi and cellular are radios, so my guess is it depends on what frequencies you wanna cover and how much extra you are willing to sacrifices in price & space.

Correct me if I'm wrong, but isnt broadcast done only manually? I.e. when you begin pairing? I guess it depends on device.

How would that prevent bot traffic?

I think most don't care about privacy, cause why would tech giant be interested in them. Especially when using more secure/private alternatives usually means you lose out in convenience, price and "quality" (how fleshed out the app is).