no need for dedicated power supply unit, power could come from computer
in case there is a dedicated power supply unit, it could be re-used for other purposes, e.g. a user that disconnects the router during night, could then use the power supply unit to charge a device like a smartphone or computer
outgoing power supply via USB PD via USB Type-C
use the router to supply power to a device like a smartphone or computer
USB data transfer
connect a storage system, e.g. a USB hard drive or USB flash drive