that's why it's good to have back-ups stored in multiple physical locations. if everything is stored in your house, your house becomes a single point of failure.
Give me an example of multiple points? You do mean about different locations outside the house or location in terms of places?It do had advantages though but same goes with disadvantages since you cant monitor it out anytime if those back-ups is still intact or already lost or found by someone.
Deep cold storage should be protected by strong encryption, so that shouldn't be an urgent concern.
My mother lives on the other side of the country -- she stores an encrypted wallet of mine in her house. Nobody can access it, and if it somehow gets lost or destroyed, she'll tell me. I don't feel like paying for a safety deposit box and I don't own any other property, so this seems like a happy medium.