Binary logic is the most common way to do things now with digital systems, but that does not imply that other digital non-binary systems do not exist.
Well, you can believe in a mythical digital system which uses non binary signals, but in reality such digital system doesn't exists.
And you're needs to accept the fact that all non binary but discrete signals are treated as analog signals and converted through ADC/DAC in order to process it in digital circuit... That is how it doing in reality
As I write this, my left wrist has a standard quartz-type wristwatch, powered from an electrochemical cell.
It contains a 32,768 Hz crystal oscillator, a binary count-down chain to produce a 1 Hz pulse train, and a digital electromechanical system with a stepper motor driving a gear chain.
The result of the gear chain is a system without any binary content whatsoever, displayed using the ancient Mesopotamian sexagesimal system (with
pars minuta prima and
pars minuta secunda on separate mechanical dials).
The discrete behavior is clearly visible: typical of a quartz watch, the second hand jumps in 1 second increments; my mechanical watch shows 1/4 second jumps.
Please take off your blinders: binary is an important subset of digital, and there is no need for two such words if they were synonymous.
You have ignored not only standard textbook definitions presented here, but practical examples of hardware that are digital but not binary, preaching the heresy that only binary counts.