Every video doorbell advertises two-way audio. Almost none of them deliver a conversation that feels like one. The usual explanation people reach for is that the microphone is cheap, and that is part of it, but it is not the main part.
Source: [Dev.to](https://dev.to/xingliao/two-way-audio-on-a-video-doorbell-is-half-duplex-and-that-is-why-the-conversation-feels-broken-215l)