Why is it that the iPhone does not allow us to start recording a video and then to flip the camera around in the opposite direction?

Why is it that the iPhone does not allow us to start recording a video and then to flip the camera around in the opposite direction?

I notice that when I record a video on my iPhone, it doesn't allow me to flip the camera angle around in the opposite direction (like it does for pictures). Why is that? Why doesn't Apple enable this feature? Are there any apps available where it is possible to flip the camera angle around in the middle of a video?

There might not be enough demand for the feature for them to bother. It does complicate things a little because you're essentially streaming video data to a file and changing cameras in the middle could [speculating here] create some timing issues while the software gets its act together.