Crypto investors are turning to Military grade vaults to safeguard their Keys. While some prefer to know the Keys by heart, some have their crypto stash in physical dedicated crypto wallets like Trezor and pay big money to have them stored in Nuclear sheltered safe vaults. Take for instance
Swiss Crypto Vault who offers Nuclear sheltered vaults to crypto investors. if you had 2000 bitcoins what options would you pick?
I don't see a need for all this high power storage

even if you have 2000 bitcoins. 2000 bitcoin sounds much now but I believe years ago, people hold this and didn't worry about anything, and likewise today, I still believe some people hold this much and more and don't have their PW stored in any military vault and the only way people know how much you own in Bitcoin is because you told them. Your keys on the diary in your home vault can also do this work.
who told you mate that
investors in the past did not mind saving their keys? or not aware of the incoming issues?
because those early adopters are the one who looks for safest way to store their coins and what?
Diary or Vault? at least you know that those places are the main target of people that will try taking your coins?
Definitely, you didn't read my post well. I never said the
investors in the past did not mind saving their keys? I said, they didn't worry about this
high power storage, and like you claim if they did worry and aware of the
incoming issues 
whatever you mean by that, why did many loss their private keys? because they were not serious about safe guiding or storing it as we do now. I can 100% tell you that I don't have such an amount of Bitcoin but with how I have stored my PKs, I am never losing them except something happens to all locations at the same time and at least you agree that Diary is just enough which is my whole point.