Not necessarily. It's most likely the hardware of the iPhone 5S that allows the Filmic app to be able to record in the robust codecs (at broadcast acceptable 50mbps versus the usual c.17mbps from the Camera app) that enables the footage to then be post-processed to the level required for this kind of destination.
No, one doesn't. Tim Cook has stated exactly why they haven't gone down that path yet. The only reason other manufacturers went bigger earlier is because of the poorer power efficiency of their hardware and software.