1.Protected connections - no corrosion when the electronics are all enclosed, away from water or oxygen in the atmosphere.
2.Safer for medical implants - for embedded medical devices, allows recharging/powering through the skin rather than having wires penetrate the skin, which would increase the risk of infection.
3.Durability - Without the need to constantly plug and unplug the device, there is significantly less wear and tear on the socket of the device and the attaching cable.