The waveform shown on an oscilloscope is a signal graph of voltage as a function of time.
Such a signal isn't considered by the oscilloscope to be traveling, and
hence the oscilloscope itself doesn't see the signal as a wave.
In the wire though, it "sort of" is a longitudinal wave of
electrons...but then again, there is more to the story. There is also a
radio EM wave in the surrounding electric and magnetic fields, and the
engineers interested in long distance signal transmission study these
fields to estimate velocity factor.
