That particular cable only works in one direction. Lightning itself can power external devices, but the whole mechanism is completely different than how USB PD

That particular cable only works in one direction. Lightning itself can power external devices, but the whole mechanism is completely different than how USB PD over USB-C works (it is designed for low power peripherals and thus can output unregulated 3-ish V in order to save on DC/DC conversion losses, similar capability of devices powered entirely from V_CONN is quite recent and hackish addition to USB-C).