Are our brains "analog"? Or are they in fact "digital"? I would think actually more digital than analog. A synapse triggers or it does not trigger. It either triggers or not, not something in between. In this sense it is 0 or 1.

Similarly transistor-based logic is based on such thresholds, when current or voltage reaches a certain level then a state-transition happens.

Well, no, synapses aren't binary in response.