Storage forensics can look into variations in charge to suggest “this used to be a 1” or “this used to be a 0”
To store more data that way, it’d have to be analog data in reality, as otherwise data loss due to charge decay would be immense so you’d need so much error checking you’d lose most of the storage savings
I doubt society will go fully paperless, there are times when you need a thing that can be crushed, folded, whatever and doesn’t run out of battery, so unless e-ink technology develops in a very specific way I don’t think every eventually will be replaced, and even without purely functional applications I think art would never ever go fully paperless for many data security (leaking art before it’s complete), economic (things are more expensive when they’re limited in supply, and making either legal or illegal copies of digital things is so much easier) and sentimental reasons (it’s just nicer to have something physical) reasons