Lightning hub audio mic adapter

As I understand it the iPhone Apple brand adapter/splitter that plugs into the iPhone with a lightning plug an has a 3.5 mm jack for headphones and a lightning port for charging but will not accommodate a microphone input into the adapter's lightning port. Why is that? Is there a lightning adapter that permits a 3.5 mm headphone and a lightning microphone input such as an iRig pro mic?

Ideally there would be a lightning up or splitter that would permit monitoring audio via a 3.5 mm headphone jack and have two lightning jacks that can be used for one or more microphones and/or for charging or backup battery, or maybe even a lightning USB drive (for external video file storage) all at the same time.