Do all USB cables have power lines?
A USB-compliant device must sense VBUS voltage level regardless whether they use their local power or not, see details here. Therefore every standard USB cable does have the VBUS and Ground wires.

An exception is a special USB 3.0 cable used/defined for Windows Debugger over USB port, it has  Type-A to Type-A plugs on both ends (non-standard for USB), usually of orange color, and no VBUS connection.