Earlier quoted context omitted.
I generally agree with you, but there's one problem with the physical key analogy. The security of physical keys is weak enough that there's always a fallback if you lose all the copies of your key: you pay a locksmith to come pick the lock and rekey it. You can't do this with digital keys because a digital key that is weak enough for this strategy to be usable is also too weak to protect you from the main class of a…
Why not print the key?
If the stuff being protected by the key is, for example, the type of data that someone would otherwise keep in a personal fire-safe, then simply printing out the keys and keeping them in that fire-safe wouldn't change the type of security being provided.
It might be nice if we had some type of highly-reliable (like the redundancy in QR codes[1]), so the process of printing out a key and re-scanning it was easy and trustworthy.