

It’s also safer, because you’re not connecting something that might carry data to the USB port. Wireless charging cannot transmit data. USB can, so delivering a virus or something that way isn’t out of the question, where it would be harder to do that over wireless charging.
Surely that would very a lot depending on where they get their energy from? Even the most measly household solar panel can deliver 10W to a charger, in which case, the energy impact would be negligible.