"Vanishingly" low by comparison? We're not talking about the 1950s. The best dynamic drivers have distortion around 0.1% at normal listening levels. How much lower are stats? And turn it up just a wee bit.....
Couple of quotes from Wiki
In virtually all electrostatic loudspeakers the diaphragm is driven by two grids, one on either side, because the force exerted on the diaphragm by a single grid will be unacceptably non-linear, thus causing harmonic distortion. Using grids on both sides cancels out voltage dependent part of non-linearity but leaves charge (attractive force) dependent part.[1] The result is near complete absence of harmonic distortion. In one recent design, the diaphragm is driven with the audio signal, with the static charge located on the grids
Advantages Edit
Advantages of electrostatic loudspeakers include:
levels of distortion one to two orders of magnitude lower than conventional cone drivers in a box[citation needed]
the extremely light weight of the diaphragm which is driven across its whole surface
exemplary frequency response (both in amplitude and phase) because the principle of generating force and pressure is almost free from resonances unlike the more common electrodynamic driver.