Technically it does very little other than (eventually) tidy up cable management, as it allows for short runs from the board to the motherboard / GPU.
It also converts PCIE to 12VHPWR if / when I change my GPU.
It also has a fan splitter and ARGB splitter built in, and if I had any it has 2 SATA mounts behind it for SSDs or 2.5" drives.