safes are very safe, the proof is that banks store fiat in safes, thieves can't open the vault, let alone impossible to take it, put it in a notebook and put it in a drawer is too easy or unnecessary material can be put in a drawer.
Who told you that Thieves can't open Vaults?we are in 20th century now mate seems like you are still in 15th century living

Talking about safeties of my Seed?i secretly put it in a urn in which i will not label here for my own safe,this may sounds disrespect but thats how i keep my asset safer,in places where no one will think that something is hidden.
At the moment I don't store any of them. I would probably use a safe to do so or have them encrypted on a computer if I stored them.
majority answer is safe place that robber or thieves will surely wanted to look at and take from you because surely there are very important that lies on those.