Advantages

• Lower risk of electrical shock or shorting out when wet because there are no exposed conductors, for example toothbrushes and shavers, or outdoors.
• Protected connections - no corrosion when the electronics are all enclosed, away from water or oxygen in the atmosphere.
• 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.
• Convenience - rather than having to connect a power cable, the device can be placed on or close to a charge plate or stand.