[OkayPhysicist]

To my understanding, the main advantage of digital over analog logic in computing was (and probably still is) its resistance to small errors. Nonlinear components like transistors and vacuum tubes aren't exactly the most consistent parts, and factors like ambient temperature can make even otherwise linear parts a little wonky. The "on/off" paradigm gives you a lot of tolerance of deviations from the ideal. Storage is also a big factor: it's really hard to store analog values, whereas on/off is approximately trivial.