We have door cameras, but they only show movement near the doors. You can hear and speak through them, but only when you press a button to do so. Ours are set to human height, but will occasionally pick up flapping sheets on the line, swooping bats or (oddly) a cat. We can't see into anyone's gardens, and the speaker facility is only used when someone is delivering something and we are away, so we can ask them to put it somewhere genuinely safe, and not leave it on the doorstep. I wouldn't want my phone to be constantly picking up random conversations anyway.
I wouldn't like a neighbour's camera trained on our house or garden, and would ask them to adjust it if they did.