Adding a data bus to all lines would be a much bigger deal than changing sockets for existing lines or running a slightly different voltage (often within tolerance of the power supplies anyway!) over the same wires.
And USB isn't meant to operate over those long distances. So you'd either need some active component in each socket or devise a new standard.
And USB isn't meant to operate over those long distances. So you'd either need some active component in each socket or devise a new standard.