Even disregarding material, it is literally less efficient due to transmission losses, and it’s only “wireless” in so far as you have a wireless dock to drop your phone on that is then attached to the wall just like a regular cable. The only thing it does is make it so you don’t have to plug a cable in or use a magnetic cable attachment, but there isn’t really any convenience gain over just having a charging cord especially if you have a super long charging cable for your stationary spots in the house.