Maybe i'm not fully grasping how it works, but i don't really see the acoustic part, aren't the resonators just turning the steel vibrations into an electric signal via coils in the same way an electric guitar works? basically what's the advantage of this vs plugin an electric guitar as a signal input to an analog synth?

Guitar strings do not generate sound, unless plucked. However there are devices like the Sustaniac and the short-lived Moog guitar that do use electromagnets to induce vibrations in the strings. So you could compare this to the Sustaniac.

EDIT - forgot about the ebow