Attack surfaces:

1. Flood (that one we had and more than once)
2. Nosy gf/wife that likes to "tidy" things up...can't happen
3. Fire
4. Something falling on the house, like a tree (impossible, right?), causing rain to wash away or soak the paper.
6. Forgetting where you put it..or if BIP 38, forgetting the password.

That said, I might have agreed a bit more if you delineated how you are circumventing the above...yes, it is doable, but require some trust in those who would hold potential copies, maybe.