[DemocracyFTW2]

There was at least one computer in the past that used quinary (if that is the term), i.e. it's vacuum tubes had five distinct voltage levels IIRC. This was done because less voltage would have meant more tubes, hence more material, more power consumption, and, importantly, more points of failure; more than five levels would've been too difficult / error prone to distinguish, also resulting in less efficiency.

It is not out of the question that some silicon blueprint could or does result in a component which can safely distinguish between more than two states.